Merge pull request #2012 from ehuss/bump-version

Update to 0.4.26

.gitattributes

@@ -0,0 +1,8 @@
+[attr]rust text eol=lf whitespace=tab-in-indent,trailing-space,tabwidth=4
+
+* text=auto eol=lf
+*.rs rust
+*.woff binary
+*.ttf binary
+*.otf binary
+*.png binary

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,45 @@
+name: Bug Report
+description: Create a report to help us improve
+labels: ["C-bug"]
+body:
+  - type: markdown
+    attributes:
+      value: Thanks for filing a 🐛 bug report 😄!
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem
+      description: >
+        Please provide a clear and concise description of what the bug is,
+        including what currently happens and what you expected to happen.
+    validations:
+      required: true
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps
+      description: Please list the steps to reproduce the bug.
+      placeholder: |
+        1.
+        2.
+        3.
+  - type: textarea
+    id: possible-solutions
+    attributes:
+      label: Possible Solution(s)
+      description: >
+        Not obligatory, but suggest a fix/reason for the bug,
+        or ideas how to implement the addition or change.
+  - type: textarea
+    id: notes
+    attributes:
+      label: Notes
+      description: Provide any additional notes that might be helpful.
+  - type: textarea
+    id: version
+    attributes:
+      label: Version
+      description: >
+        Please paste the output of running `mdbook --version` or which version
+        of the library you are using.
+      render: text

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,28 @@
+name: Enhancement
+description: Suggest an idea for enhancing mdBook
+labels: ["C-enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for filing a 🙋 feature request 😄!
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem
+      description: >
+        Please provide a clear description of your use case and the problem
+        this feature request is trying to solve.
+    validations:
+      required: true
+  - type: textarea
+    id: solution
+    attributes:
+      label: Proposed Solution
+      description: >
+        Please provide a clear and concise description of what you want to happen.
+  - type: textarea
+    id: notes
+    attributes:
+      label: Notes
+      description: Provide any additional context or information that might be helpful.

.github/ISSUE_TEMPLATE/question.yml

@@ -0,0 +1,24 @@
+name: Question
+description: Have a question on how to use mdBook?
+labels: ["C-question"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Got a question on how to do something with mdBook?
+  - type: textarea
+    id: question
+    attributes:
+      label: Question
+      description: >
+        Enter your question here. Please try to provide as much detail as possible.
+    validations:
+      required: true
+  - type: textarea
+    id: version
+    attributes:
+      label: Version
+      description: >
+        Please paste the output of running `mdbook --version` or which version
+        of the library you are using.
+      render: text

.github/workflows/deploy.yml

@@ -0,0 +1,58 @@
+name: Deploy
+on:
+  release:
+    types: [created]
+
+jobs:
+  release:
+    name: Deploy Release
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        target:
+          - aarch64-unknown-linux-musl
+          - x86_64-unknown-linux-gnu
+          - x86_64-unknown-linux-musl
+          - x86_64-apple-darwin
+          - x86_64-pc-windows-msvc
+        include:
+          - target: aarch64-unknown-linux-musl
+            os: ubuntu-20.04
+          - target: x86_64-unknown-linux-gnu
+            os: ubuntu-20.04
+          - target: x86_64-unknown-linux-musl
+            os: ubuntu-20.04
+          - target: x86_64-apple-darwin
+            os: macos-latest
+          - target: x86_64-pc-windows-msvc
+            os: windows-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install hub
+      run: ci/install-hub.sh ${{ matrix.os }}
+      shell: bash
+    - name: Install Rust
+      run: ci/install-rust.sh stable ${{ matrix.target }}
+      shell: bash
+    - name: Build and deploy artifacts
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: ci/make-release.sh ${{ matrix.os }} ${{ matrix.target }}
+      shell: bash
+  pages:
+    name: GitHub Pages
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust (rustup)
+      run: rustup update stable --no-self-update && rustup default stable
+    - name: Build book
+      run: cargo run -- build guide
+    - name: Deploy to GitHub
+      env:
+        GITHUB_DEPLOY_KEY: ${{ secrets.GITHUB_DEPLOY_KEY }}
+      run: |
+        touch guide/book/.nojekyll
+        curl -LsSf https://raw.githubusercontent.com/rust-lang/simpleinfra/master/setup-deploy-keys/src/deploy.rs | rustc - -o /tmp/deploy
+        cd guide/book
+        /tmp/deploy

.github/workflows/main.yml

@@ -0,0 +1,52 @@
+name: CI
+on:
+  # Only run when merging to master, or open/synchronize/reopen a PR.
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  test:
+    name: Test
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        build: [stable, beta, nightly, macos, windows, msrv]
+        include:
+          - build: stable
+            os: ubuntu-latest
+            rust: stable
+          - build: beta
+            os: ubuntu-latest
+            rust: beta
+          - build: nightly
+            os: ubuntu-latest
+            rust: nightly
+          - build: macos
+            os: macos-latest
+            rust: stable
+          - build: windows
+            os: windows-latest
+            rust: stable
+          - build: msrv
+            os: ubuntu-20.04
+            # sync MSRV with docs: guide/src/guide/installation.md and Cargo.toml
+            rust: 1.60.0
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust
+      run: bash ci/install-rust.sh ${{ matrix.rust }}
+    - name: Build and run tests
+      run: cargo test
+    - name: Test no default
+      run: cargo test --no-default-features
+
+  rustfmt:
+    name: Rustfmt
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust
+      run: rustup update stable && rustup default stable && rustup component add rustfmt
+    - run: cargo fmt --check

.gitignore

@@ -1,5 +1,18 @@
-Cargo.lock
 target
 
+# MacOS temp file
+.DS_Store
+
 book-test
-book-example/book
+guide/book
+
+.vscode
+tests/dummy_book/book/
+test_book/book/
+
+# Ignore Jetbrains specific files.
+.idea/
+
+# Ignore Vim temporary and swap files.
+*.sw?
+*~

.travis.yml

@@ -1,20 +0,0 @@
-language: rust
-rust:
-- stable
-- beta
-- nightly
-matrix:
-  allow_failure:
-  - rust: nightly
-env:
-  global:
-    secure: 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
-addons:
-  apt:
-    packages:
-    - nodejs
-    - npm
-install:
-    - npm install stylus nib
-after_success:
-  - test $TRAVIS_PULL_REQUEST == "false" && test $TRAVIS_BRANCH == "master" && bash deploy.sh

CHANGELOG.md

@@ -0,0 +1,898 @@
+# Changelog
+
+## mdBook 0.4.26
+[v0.4.25...v0.4.26](https://github.com/rust-lang/mdBook/compare/v0.4.25...v0.4.26)
+
+### Changed
+- Removed custom scrollbars for webkit browsers
+  [#1961](https://github.com/rust-lang/mdBook/pull/1961)
+- Updated some dependencies
+  [#1998](https://github.com/rust-lang/mdBook/pull/1998)
+  [#2009](https://github.com/rust-lang/mdBook/pull/2009)
+  [#2011](https://github.com/rust-lang/mdBook/pull/2011)
+- Fonts are now part of the theme.
+  The `output.html.copy-fonts` option has been deprecated.
+  To define custom fonts, be sure to define `theme/fonts.css`.
+  [#1987](https://github.com/rust-lang/mdBook/pull/1987)
+
+### Fixed
+- Fixed overflow viewport issue with mobile Safari
+  [#1994](https://github.com/rust-lang/mdBook/pull/1994)
+
+## mdBook 0.4.25
+[e14d381...1ba74a3](https://github.com/rust-lang/mdBook/compare/e14d381...1ba74a3)
+
+### Fixed
+- Fixed a regression where `mdbook test -L deps path-to-book` would not work.
+  [#1959](https://github.com/rust-lang/mdBook/pull/1959)
+
+## mdBook 0.4.24
+[eb77083...8767ebf](https://github.com/rust-lang/mdBook/compare/eb77083...8767ebf)
+
+### Fixed
+- The precompiled linux-gnu mdbook binary available on [GitHub Releases](https://github.com/rust-lang/mdBook/releases) inadvertently switched to a newer version of glibc. This release goes back to an older version that should be more compatible on older versions of Linux.
+  [#1955](https://github.com/rust-lang/mdBook/pull/1955)
+
+## mdBook 0.4.23
+[678b469...68a75da](https://github.com/rust-lang/mdBook/compare/678b469...68a75da)
+
+### Changed
+- Updated all dependencies
+  [#1951](https://github.com/rust-lang/mdBook/pull/1951)
+  [#1952](https://github.com/rust-lang/mdBook/pull/1952)
+  [#1844](https://github.com/rust-lang/mdBook/pull/1844)
+- Updated minimum Rust version to 1.60.
+  [#1951](https://github.com/rust-lang/mdBook/pull/1951)
+
+### Fixed
+- Fixed a regression where playground code was missing hidden lines, preventing it from compiling correctly.
+  [#1950](https://github.com/rust-lang/mdBook/pull/1950)
+
+## mdBook 0.4.22
+[40c06f5...4844f72](https://github.com/rust-lang/mdBook/compare/40c06f5...4844f72)
+
+### Added
+- Added a `--chapter` option to `mdbook test` to specify a specific chapter to test.
+  [#1741](https://github.com/rust-lang/mdBook/pull/1741)
+- Added CSS styling for `<kbd>` tags.
+  [#1906](https://github.com/rust-lang/mdBook/pull/1906)
+- Added pre-compiled binaries for `x86_64-unknown-linux-musl` and `aarch64-unknown-linux-musl` (see [Releases](https://github.com/rust-lang/mdBook/releases)).
+  [#1862](https://github.com/rust-lang/mdBook/pull/1862)
+- Added `build.extra-watch-dirs` which is an array of additional directories to watch for changes when running `mdbook serve`.
+  [#1884](https://github.com/rust-lang/mdBook/pull/1884)
+
+### Changed
+- Removed the `type="text/javascript"` attribute from `<script>` tags.
+  [#1881](https://github.com/rust-lang/mdBook/pull/1881)
+- Switched to building with Rust Edition 2021.
+  This raises the minimum supported Rust version to 1.56.
+  [#1887](https://github.com/rust-lang/mdBook/pull/1887)
+- When hidden code is hidden, the hidden parts are no longer copied to the clipboard via the copy button.
+  [#1911](https://github.com/rust-lang/mdBook/pull/1911)
+- Various HTML changes and fixes to be more compliant with HTML5.
+  [#1924](https://github.com/rust-lang/mdBook/pull/1924)
+- The theme picker now shows which theme is currently selected.
+  [#1935](https://github.com/rust-lang/mdBook/pull/1935)
+
+### Fixed
+- Avoid blank line at the end of an ACE code block
+  [#1836](https://github.com/rust-lang/mdBook/pull/1836)
+
+
+## mdBook 0.4.21
+[92afe9b...8f01d02](https://github.com/rust-lang/mdBook/compare/92afe9b...8f01d02)
+
+### Fixed
+- Fixed an issue where mdBook would fail to compile with Rust nightly-2022-07-22.
+  [#1861](https://github.com/rust-lang/mdBook/pull/1861)
+
+## mdBook 0.4.20
+[53055e0...da166e0](https://github.com/rust-lang/mdBook/compare/53055e0...da166e0)
+
+### Fixed
+- Fixed a regression in 0.4.19 where inline code would have excessive padding
+  in some situations such as headings.
+  [#1855](https://github.com/rust-lang/mdBook/pull/1855)
+
+## mdBook 0.4.19
+[ae275ad...53055e0](https://github.com/rust-lang/mdBook/compare/ae275ad...53055e0)
+
+### Added
+- The `serve` command now supports HEAD requests.
+  [#1825](https://github.com/rust-lang/mdBook/pull/1825)
+
+### Changed
+- An error is now generated when a custom theme directory does not exist.
+  [#1791](https://github.com/rust-lang/mdBook/pull/1791)
+- Very wide tables now have independent horizontal scrolling so that scrolling
+  to see the rest of the table will not scroll the entire page.
+  [#1617](https://github.com/rust-lang/mdBook/pull/1617)
+- The buttons on code blocks are now only shown when the mouse cursor hovers
+  over them (or tapped on mobile). There is also some extra spacing to reduce
+  the overlap with the code.
+  [#1806](https://github.com/rust-lang/mdBook/pull/1806)
+- The first chapter always generates an `index.html` file. Previously it would
+  only generate the index file for prefix chapters.
+  [#1829](https://github.com/rust-lang/mdBook/pull/1829)
+
+### Fixed
+- `mdbook serve --open` now properly handles the case if the first chapter is a draft.
+  [#1714](https://github.com/rust-lang/mdBook/pull/1714)
+  [#1830](https://github.com/rust-lang/mdBook/pull/1830)
+- Very long words (over 80 characters) are no longer indexed to avoid a stack overflow.
+  [#1833](https://github.com/rust-lang/mdBook/pull/1833)
+
+## mdBook 0.4.18
+[981b79b...ae275ad](https://github.com/rust-lang/mdBook/compare/981b79b...ae275ad)
+
+### Fixed
+- Fixed rendering of SUMMARY links that contain markdown escapes or other
+  markdown elements.
+  [#1785](https://github.com/rust-lang/mdBook/pull/1785)
+
+## mdBook 0.4.17
+[a5fddfa...981b79b](https://github.com/rust-lang/mdBook/compare/a5fddfa...981b79b)
+
+### Fixed
+- Fixed parsing of `output.html.print` configuration table.
+  [#1775](https://github.com/rust-lang/mdBook/pull/1775)
+
+## mdBook 0.4.16
+[68a5c09...a5fddfa](https://github.com/rust-lang/mdBook/compare/68a5c09...a5fddfa)
+
+### Added
+- Added `output.html.print.page-break` config option to control whether or not
+  there is a page break between chapters in the print output.
+  [#1728](https://github.com/rust-lang/mdBook/pull/1728)
+- Added `output.html.playground.runnable` config option to globally disable
+  the run button in code blocks.
+  [#1546](https://github.com/rust-lang/mdBook/pull/1546)
+
+### Changed
+- The `mdbook serve` live reload websocket now uses the protocol, host, and
+  port of the current page, allowing access through a proxy.
+  [#1771](https://github.com/rust-lang/mdBook/pull/1771)
+- The 404 not-found page now includes the books title in the HTML title tag.
+  [#1693](https://github.com/rust-lang/mdBook/pull/1693)
+- Migrated to clap 3.0 which which handles CLI option parsing.
+  [#1731](https://github.com/rust-lang/mdBook/pull/1731)
+
+### Fixed
+- Minor fixes to the markdown parser.
+  [#1729](https://github.com/rust-lang/mdBook/pull/1729)
+- Fixed incorrect parsing in `SUMMARY.md` when it didn't start with a title.
+  [#1744](https://github.com/rust-lang/mdBook/pull/1744)
+- Fixed duplicate anchor IDs for links in search results.
+  [#1749](https://github.com/rust-lang/mdBook/pull/1749)
+
+## mdBook 0.4.15
+[5eb7d46...68a5c09](https://github.com/rust-lang/mdBook/compare/5eb7d46...68a5c09)
+
+### Changed
+- Major update to expand the documentation located at <https://rust-lang.github.io/mdBook/>.
+  [#1709](https://github.com/rust-lang/mdBook/pull/1709)
+  [#1710](https://github.com/rust-lang/mdBook/pull/1710)
+- Updated the markdown parser with various fixes for common-mark compliance.
+  [#1712](https://github.com/rust-lang/mdBook/pull/1712)
+
+## mdBook 0.4.14
+[ffa8284...c9b6be8](https://github.com/rust-lang/mdBook/compare/ffa8284...c9b6be8)
+
+### Added
+- The 2021 Rust edition option has been stabilized.
+  [#1642](https://github.com/rust-lang/mdBook/pull/1642)
+
+### Changed
+- Header anchors no longer include any HTML tags. Previously only a small
+  subset were excluded.
+  [#1683](https://github.com/rust-lang/mdBook/pull/1683)
+- Deprecated the google-analytics option. Books using this option should place
+  the appropriate code in the `theme/head.hbs` file instead.
+  [#1675](https://github.com/rust-lang/mdBook/pull/1675)
+
+### Fixed
+- Updated the markdown parser which brings in a few small fixes and removes
+  the custom smart quote handling.
+  [#1668](https://github.com/rust-lang/mdBook/pull/1668)
+- Fixed iOS Safari enlarging text when going into landscape mode.
+  [#1685](https://github.com/rust-lang/mdBook/pull/1685)
+
+## mdBook 0.4.13
+[e6629cd...f55028b](https://github.com/rust-lang/mdBook/compare/e6629cd...f55028b)
+
+### Added
+
+- Added the ability to specify the preprocessor order.
+  [#1607](https://github.com/rust-lang/mdBook/pull/1607)
+
+### Fixed
+
+- Include chapters with no headers in the search index
+  [#1637](https://github.com/rust-lang/mdBook/pull/1637)
+- Switched to the `opener` crate for opening a web browser, which should fix
+  some issues with blocking.
+  [#1656](https://github.com/rust-lang/mdBook/pull/1656)
+- Fixed clicking the border of the theme switcher breaking the theme selection.
+  [#1651](https://github.com/rust-lang/mdBook/pull/1651)
+
+## mdBook 0.4.12
+[14add9c...8b4e488](https://github.com/rust-lang/mdBook/compare/14add9c...8b4e488)
+
+### Changed
+- Reverted the change to update to highlight.js 11, as it broke hidden code lines.
+  [#1597](https://github.com/rust-lang/mdBook/pull/1621)
+ 
+## mdBook 0.4.11
+[e440094...2cf00d0](https://github.com/rust-lang/mdBook/compare/e440094...2cf00d0)
+
+### Added
+- Added support for Rust 2021 edition.
+  [#1596](https://github.com/rust-lang/mdBook/pull/1596)
+- Added `mdbook completions` subcommand which provides shell completions.
+  [#1425](https://github.com/rust-lang/mdBook/pull/1425)
+- Added `--title` and `--ignore` flags to `mdbook init` to avoid the
+  interactive input.
+  [#1559](https://github.com/rust-lang/mdBook/pull/1559)
+
+### Changed
+- If running a Rust example does not have any output, it now displays the text
+  "No output" instead of not showing anything.
+  [#1599](https://github.com/rust-lang/mdBook/pull/1599)
+- Code block language tags can now be separated by space or tab (along with
+  commas) to match the behavior of other sites like GitHub and rustdoc.
+  [#1469](https://github.com/rust-lang/mdBook/pull/1469)
+- Updated `warp` (the web server) to the latest version.
+  This also updates the minimum supported Rust version to 1.46.
+  [#1612](https://github.com/rust-lang/mdBook/pull/1612)
+- Updated to highlight.js 11. This has various highlighting improvements.
+  [#1597](https://github.com/rust-lang/mdBook/pull/1597)
+
+### Fixed
+- Inline code blocks inside a header are no longer highlighted when
+  `output.html.playground.editable` is `true`.
+  [#1613](https://github.com/rust-lang/mdBook/pull/1613)
+
+## mdBook 0.4.10
+[2f7293a...dc2062a](https://github.com/rust-lang/mdBook/compare/2f7293a...dc2062a)
+
+### Changed
+- Reverted breaking change in 0.4.9 that removed the `__non_exhaustive` marker
+  on the `Book` struct.
+  [#1572](https://github.com/rust-lang/mdBook/pull/1572)
+- Updated handlebars to 4.0.
+  [#1550](https://github.com/rust-lang/mdBook/pull/1550)
+- Removed the `chapter_begin` id on the print page's chapter separators.
+  [#1541](https://github.com/rust-lang/mdBook/pull/1541)
+
+## mdBook 0.4.9
+[7e01cf9...d325c60](https://github.com/rust-lang/mdBook/compare/7e01cf9...d325c60)
+
+### Changed
+- Updated all dependencies and raised the minimum Rust version to 1.42.
+  [#1528](https://github.com/rust-lang/mdBook/pull/1528)
+- Added more detail to error message when a preprocessor fails.
+  [#1526](https://github.com/rust-lang/mdBook/pull/1526)
+- Set max-width of HTML video tags to 100% to match img tags.
+  [#1542](https://github.com/rust-lang/mdBook/pull/1542)
+
+### Fixed
+- Type errors when parsing `book.toml` are no longer ignored.
+  [#1539](https://github.com/rust-lang/mdBook/pull/1539)
+- Better handling if `mdbook serve` fails to start the http server.
+  [#1555](https://github.com/rust-lang/mdBook/pull/1555)
+- Fixed the path for `edit-url-template` if the book used a source directory
+  other than `src`.
+  [#1554](https://github.com/rust-lang/mdBook/pull/1554)
+
+## mdBook 0.4.8
+[fcceee4...b592b10](https://github.com/rust-lang/mdBook/compare/fcceee4...b592b10)
+
+### Added
+- Added the option `output.html.edit-url-template` which can be a URL which is
+  linked on each page to direct the user to a site (such as GitHub) where the
+  user can directly suggest an edit for the page they are currently reading.
+  [#1506](https://github.com/rust-lang/mdBook/pull/1506)
+
+### Changed
+- Printed output now includes a page break between chapters.
+  [#1485](https://github.com/rust-lang/mdBook/pull/1485)
+
+### Fixed
+- HTML, such as HTML comments, is now ignored if it appears above the title line
+  in `SUMMARY.md`.
+  [#1437](https://github.com/rust-lang/mdBook/pull/1437)
+
+## mdBook 0.4.7
+[9a9eb01...c83bbd6](https://github.com/rust-lang/mdBook/compare/9a9eb01...c83bbd6)
+
+### Changed
+- Updated shlex parser to fix a minor parsing issue (used by the
+  preprocessor/backend custom command config).
+  [#1471](https://github.com/rust-lang/mdBook/pull/1471)
+- Enhanced text contrast of `light` theme to improve accessibility.
+  [#1470](https://github.com/rust-lang/mdBook/pull/1470)
+
+### Fixed
+- Fixed some issues with fragment scrolling and linking.
+  [#1463](https://github.com/rust-lang/mdBook/pull/1463)
+
+## mdBook 0.4.6
+[eaa6914...1a0c296](https://github.com/rust-lang/mdBook/compare/eaa6914...1a0c296)
+
+### Changed
+- The chapter name is now included in the search breadcrumbs.
+  [#1389](https://github.com/rust-lang/mdBook/pull/1389)
+- Pressing Escape will remove the `?highlight` argument from the URL.
+  [#1427](https://github.com/rust-lang/mdBook/pull/1427)
+- `mdbook init --theme` will now place the theme in the root of the book
+  directory instead of in the `src` directory.
+  [#1432](https://github.com/rust-lang/mdBook/pull/1432)
+- A custom renderer that sets the `command` to a relative path now interprets
+  the relative path relative to the book root. Previously it was inconsistent
+  based on the platform (either relative to the current directory, or relative
+  to the renderer output directory). Paths relative to the output directory
+  are still supported with a deprecation warning.
+  [#1418](https://github.com/rust-lang/mdBook/pull/1418)
+- The `theme` directory in the config is now interpreted as relative to the
+  book root, instead of the current directory.
+  [#1405](https://github.com/rust-lang/mdBook/pull/1405)
+- Handle UTF-8 BOM for chapter sources.
+  [#1285](https://github.com/rust-lang/mdBook/pull/1285)
+- Removed extra whitespace added to `{{#playground}}` snippets.
+  [#1375](https://github.com/rust-lang/mdBook/pull/1375)
+
+### Fixed
+- Clicking on a search result with multiple search words will now correctly
+  highlight all of the words.
+  [#1426](https://github.com/rust-lang/mdBook/pull/1426)
+- Properly handle `<` and `>` characters in the table of contents.
+  [#1376](https://github.com/rust-lang/mdBook/pull/1376)
+- Fixed to properly serialize the `build` table in the config, which prevented
+  setting it in the API.
+  [#1378](https://github.com/rust-lang/mdBook/pull/1378)
+
+## mdBook 0.4.5
+[eaa6914...f66df09](https://github.com/rust-lang/mdBook/compare/eaa6914...f66df09)
+
+### Fixed
+
+- Fixed XSS in the search page.
+  [CVE-2020-26297](https://groups.google.com/g/rustlang-security-announcements/c/3-sO6of29O0)
+  [648c9ae](https://github.com/rust-lang/mdBook/commit/648c9ae772bec83f0a5954d17b4287d5bb1d6606)
+
+## mdBook 0.4.4
+[4df9ec9...01836ba](https://github.com/rust-lang/mdBook/compare/4df9ec9...01836ba)
+
+### Added
+- Added the `output.html.print.enable` configuration value to disable the
+  "print" page.
+  [#1169](https://github.com/rust-lang/mdBook/pull/1169)
+- Added a list of supported languages for syntax-highlighting to the
+  documentation.
+  [#1345](https://github.com/rust-lang/mdBook/pull/1345)
+
+### Fixed
+- Now supports symbolic links for files in the `src` directory.
+  [#1323](https://github.com/rust-lang/mdBook/pull/1323)
+
+## mdBook 0.4.3
+[9278b83...4df9ec9](https://github.com/rust-lang/mdBook/compare/9278b83...4df9ec9)
+
+### Added
+- Added `output.html.cname` option to emit a `CNAME` file which is used by
+  GitHub Pages to know which domain is being used.
+  [#1311](https://github.com/rust-lang/mdBook/pull/1311)
+
+### Changed
+- `mdbook test` no longer stops on the first test failure, but instead will
+  run all the tests.
+  [#1313](https://github.com/rust-lang/mdBook/pull/1313)
+- Removed the `local` font source for Source Code Pro, as the locally
+  installed font may not render properly on FireFox on macOS.
+  [#1307](https://github.com/rust-lang/mdBook/pull/1307)
+
+### Fixed
+- Added newline to end of `.nojekyll` file.
+  [#1310](https://github.com/rust-lang/mdBook/pull/1310)
+- Fixed missing space before draft chapter titles.
+  [#1309](https://github.com/rust-lang/mdBook/pull/1309)
+
+## mdBook 0.4.2
+[649f355...9278b83](https://github.com/rust-lang/mdBook/compare/649f355...9278b83)
+
+### Changed
+- The "show hidden lines" icon has changed from the "expand" icon to an "eye".
+  [#1281](https://github.com/rust-lang/mdBook/pull/1281)
+- Updated highlight.js. This adds several languages: c, c-like (effectively
+  cpp), csharp (replaces cs), kotlin, less, lua, php-template, plaintext,
+  python-repl, r, scss, typescript.
+  [#1277](https://github.com/rust-lang/mdBook/pull/1277)
+
+### Fixed
+- Fixed SUMMARY links that contained newlines.
+  [#1291](https://github.com/rust-lang/mdBook/pull/1291)
+- Fixed SUMMARY links that contain `%20` spaces.
+  [#1293](https://github.com/rust-lang/mdBook/pull/1293)
+- Fixed favicon so that if only the png or svg is overridden, the other is not
+  automatically included in the `<link>` tag.
+  [#1272](https://github.com/rust-lang/mdBook/pull/1272)
+
+## mdBook 0.4.1
+[d4df7e7...649f355](https://github.com/rust-lang/mdBook/compare/d4df7e7...649f355)
+
+### Changed
+- Removed several outdated dev-dependencies.
+  [#1267](https://github.com/rust-lang/mdBook/pull/1267)
+
+### Fixed
+- Fixed sidebar scrolling if the book includes part titles.
+  [#1265](https://github.com/rust-lang/mdBook/pull/1265)
+- Don't include the default favicon if only one of the PNG or SVG is overridden.
+  [#1266](https://github.com/rust-lang/mdBook/pull/1266)
+
+## mdBook 0.4.0
+[99ecd4f...d4df7e7](https://github.com/rust-lang/mdBook/compare/99ecd4f...d4df7e7)
+
+### Breaking Changes
+- Several of the changes in the release have altered the public API of the
+  mdbook library.
+- Many dependencies have been updated or replaced.
+  This also removes the `--websocket-hostname` and `--websocket-port` from
+  the `serve` command.
+  [#1211](https://github.com/rust-lang/mdBook/pull/1211)
+- A new "404" page is now automatically rendered. This requires knowledge of
+  the base URL of your site to work properly. If you decide to use this as
+  your 404 page, you should set the `site-url` setting in the book
+  configuration so mdbook can generate the links correctly. Alternatively you
+  can disable the 404 page generation, or set up your own 404 handling in your
+  web server.
+  [#1221](https://github.com/rust-lang/mdBook/pull/1221)
+- The `debug` and `output` features have been removed as they were unused.
+  [#1211](https://github.com/rust-lang/mdBook/pull/1211)
+- If you are using customized themes, you may want to consider setting the
+  `preferred-dark-theme` config setting, as it now defaults to "navy".
+  [#1199](https://github.com/rust-lang/mdBook/pull/1199)
+- "Playpen" has been renamed to "playground". This is generally backwards
+  compatible for users, but `{{#playpen}}` will now display warnings. This may
+  impact books that have modified the "playpen" elements in the theme.
+  [#1241](https://github.com/rust-lang/mdBook/pull/1241)
+- If a renderer is not installed, it is now treated as an error. If you want
+  the old behavior of ignoring missing renderers, set the `optional` setting
+  for that renderer.
+  [#1122](https://github.com/rust-lang/mdBook/pull/1122)
+- If you have a custom favicon, you may need to look into adding an SVG
+  version, otherwise the default SVG icon will be displayed.
+  [#1230](https://github.com/rust-lang/mdBook/pull/1230)
+
+### Added
+- Added a new `[rust]` configuration section to `book.toml`, which allows
+  setting the default edition with `edition = "2018"`.
+  [#1163](https://github.com/rust-lang/mdBook/pull/1163)
+- Renderers can now be marked as `optional`, so that they will be ignored if
+  the renderer is not installed.
+  [#1122](https://github.com/rust-lang/mdBook/pull/1122)
+- Added `head.hbs` to allow adding content to the `<head>` section in HTML.
+  [#1206](https://github.com/rust-lang/mdBook/pull/1206)
+- Added "draft chapters". These are chapters listed without a link to indicate
+  content yet to be written.
+  [#1153](https://github.com/rust-lang/mdBook/pull/1153)
+- Added "parts" to split a book into different sections. Headers can be added
+  to `SUMMARY.md` to signify different sections.
+  [#1171](https://github.com/rust-lang/mdBook/pull/1171)
+- Added generation of a "404" page for handling missing pages and broken links.
+  [#1221](https://github.com/rust-lang/mdBook/pull/1221)
+- Added configuration section for specifying URL redirects.
+  [#1237](https://github.com/rust-lang/mdBook/pull/1237)
+- Added an SVG favicon that works with light and dark colors schemes.
+  [#1230](https://github.com/rust-lang/mdBook/pull/1230)
+
+### Changed
+- Changed default Rust attribute of `allow(unused_variables)` to `allow(unused)`.
+  [#1195](https://github.com/rust-lang/mdBook/pull/1195)
+- Fonts are now served locally instead of from the Google Fonts CDN. The
+  `copy-fonts` option was added to disable this if you want to supply your own
+  fonts.
+  [#1188](https://github.com/rust-lang/mdBook/pull/1188)
+- Switched the built-in webserver for the `serve` command to a new
+  implementation. This results in some internal differences in how websockets
+  are handled, which removes the separate websocket options. This should also
+  make it easier to serve multiple books at once.
+  [#1211](https://github.com/rust-lang/mdBook/pull/1211)
+- The default dark theme is now "navy".
+  [#1199](https://github.com/rust-lang/mdBook/pull/1199)
+- "Playpen" has been renamed to "playground", matching the actual name of the
+  service which was renamed many years ago.
+  [#1241](https://github.com/rust-lang/mdBook/pull/1241)
+
+### Fixed
+- Links with the `+` symbol should now work.
+  [#1208](https://github.com/rust-lang/mdBook/pull/1208)
+- The `MDBOOK_BOOK` environment variable now correctly allows overriding the
+  entire book configuration.
+  [#1207](https://github.com/rust-lang/mdBook/pull/1207)
+- The sidebar can no longer be dragged outside of the window.
+  [#1229](https://github.com/rust-lang/mdBook/pull/1229)
+- Hide the Rust Playground "play" button for `no_run` code samples.
+  [#1249](https://github.com/rust-lang/mdBook/pull/1249)
+- Fixed the `--dest-dir` command-line option for the `serve` and `watch`
+  commands.
+  [#1228](https://github.com/rust-lang/mdBook/pull/1228)
+- Hotkey handlers are now disabled in `text` input fields (for example, typing
+  `S` in a custom text input field).
+  [#1244](https://github.com/rust-lang/mdBook/pull/1244)
+
+## mdBook 0.3.7
+[88684d8...99ecd4f](https://github.com/rust-lang/mdBook/compare/88684d8...99ecd4f)
+
+### Changed
+- Code spans in headers are no longer highlighted as code.
+  [#1162](https://github.com/rust-lang/mdBook/pull/1162)
+- The sidebar will now scroll the activate page to the middle instead of the top.
+  [#1161](https://github.com/rust-lang/mdBook/pull/1161)
+- Reverted change to reject build output within the `src` directory, and
+  instead add a check that prevents infinite copies.
+  [#1181](https://github.com/rust-lang/mdBook/pull/1181)
+  [#1026](https://github.com/rust-lang/mdBook/pull/1026)
+
+### Fixed
+- Fixed sidebar line-height jumping for collapsed chapters.
+  [#1182](https://github.com/rust-lang/mdBook/pull/1182)
+- Fixed theme selector focus.
+  [#1170](https://github.com/rust-lang/mdBook/pull/1170)
+
+## mdBook 0.3.6
+[efdb832...88684d8](https://github.com/rust-lang/mdBook/compare/efdb832...88684d8)
+
+### Added
+- `MDBook::execute_build_process` is now publicly accessible in the API so
+  that plugins can more easily initiate the build process.
+  [#1099](https://github.com/rust-lang/mdBook/pull/1099)
+
+### Changed
+- Use a different color for Ayu theme's highlighting for Rust attributes (uses
+  a bright color instead of the comment color).
+  [#1133](https://github.com/rust-lang/mdBook/pull/1133)
+- Adjusted spacing of sidebar entries.
+  [#1137](https://github.com/rust-lang/mdBook/pull/1137)
+- Slightly adjusted line-height of `<p>`, `<ul>`, and `<ol>`.
+  [#1136](https://github.com/rust-lang/mdBook/pull/1136)
+- Handlebars updated to 3.0.
+  [#1130](https://github.com/rust-lang/mdBook/pull/1130)
+
+### Fixed
+- Fix an issue with sidebar scroll position on reload.
+  [#1108](https://github.com/rust-lang/mdBook/pull/1108)
+- `mdbook serve` will retain the current scroll position when the page is reloaded.
+  [#1097](https://github.com/rust-lang/mdBook/pull/1097)
+- Fixed the page name if the book didn't have a title to not be prefixed with ` - `.
+  [#1145](https://github.com/rust-lang/mdBook/pull/1145)
+- HTML attributes `rel=next` and `rel=previous` are now supported in "wide"
+  mode (previously they were only set in narrow mode).
+  [#1150](https://github.com/rust-lang/mdBook/pull/1150)
+- Prevent recursive copies when the destination directory is contained in the
+  source directory.
+  [#1135](https://github.com/rust-lang/mdBook/pull/1135)
+- Adjusted the menu bar animation to not immediately obscure the top content.
+  [#989](https://github.com/rust-lang/mdBook/pull/989)
+- Fix for comments in SUMMARY.md that appear between items.
+  [#1167](https://github.com/rust-lang/mdBook/pull/1167)
+
+## mdBook 0.3.5
+[6e0d0fa...efdb832](https://github.com/rust-lang/mdBook/compare/6e0d0fa...efdb832)
+
+### Changed
+- The `default-theme` config setting is now case-insensitive.
+  [#1079](https://github.com/rust-lang/mdBook/pull/1079)
+
+### Fixed
+- Fixed `#` hidden Rust code lines not rendering properly.
+  [#1088](https://github.com/rust-lang/mdBook/pull/1088)
+- Updated pulldown-cmark to 0.6.1, fixing several issues.
+  [#1021](https://github.com/rust-lang/mdBook/pull/1021)
+
+## mdBook 0.3.4
+[e5f77aa...6e0d0fa](https://github.com/rust-lang/mdBook/compare/e5f77aa...6e0d0fa)
+
+### Changed
+- Switch to relative `rem` font sizes from `px`.
+  [#894](https://github.com/rust-lang/mdBook/pull/894)
+- Migrated repository to https://github.com/rust-lang/mdBook/
+  [#1083](https://github.com/rust-lang/mdBook/pull/1083)
+
+## mdBook 0.3.3
+[2b649fe...e5f77aa](https://github.com/rust-lang/mdBook/compare/2b649fe...e5f77aa)
+
+### Changed
+- Improvements to the automatic dark theme selection.
+  [#1069](https://github.com/rust-lang/mdBook/pull/1069)
+- Fragment links now prevent scrolling the header behind the menu bar.
+  [#1077](https://github.com/rust-lang/mdBook/pull/1077)
+
+### Fixed
+- Fixed error when building a book that has a spacer immediately after the
+  first chapter.
+  [#1075](https://github.com/rust-lang/mdBook/pull/1075)
+
+## mdBook 0.3.2
+[9cd47eb...2b649fe](https://github.com/rust-lang/mdBook/compare/9cd47eb...2b649fe)
+
+### Added
+- Added a markdown renderer, which is off by default. This may be useful for
+  debugging preprocessors.
+  [#1018](https://github.com/rust-lang/mdBook/pull/1018)
+- Code samples may now include line numbers with the
+  `output.html.playpen.line-numbers` configuration value.
+  [#1035](https://github.com/rust-lang/mdBook/pull/1035)
+- The `watch` and `serve` commands will now ignore files listed in
+  `.gitignore`.
+  [#1044](https://github.com/rust-lang/mdBook/pull/1044)
+- Added automatic dark-theme detection based on the CSS `prefers-color-scheme`
+  feature. This may be enabled by setting `output.html.preferred-dark-theme`
+  to your preferred dark theme.
+  [#1037](https://github.com/rust-lang/mdBook/pull/1037)
+- Added `rustdoc_include` preprocessor. This makes it easier to include
+  portions of an external Rust source file. The rest of the file is hidden,
+  but the user may expand it to see the entire file, and will continue to work
+  with `mdbook test`.
+  [#1003](https://github.com/rust-lang/mdBook/pull/1003)
+- Added Ctrl-Enter shortcut to the playpen editor to automatically run the
+  sample.
+  [#1066](https://github.com/rust-lang/mdBook/pull/1066)
+- Added `output.html.playpen.copyable` configuration option to disable
+  the copy button.
+  [#1050](https://github.com/rust-lang/mdBook/pull/1050)
+- Added ability to dynamically expand and fold sections within the sidebar.
+  See the `output.html.fold` configuration to enable this feature.
+  [#1027](https://github.com/rust-lang/mdBook/pull/1027)
+
+### Changed
+- Use standard `scrollbar-color` CSS along with webkit extension
+  [#816](https://github.com/rust-lang/mdBook/pull/816)
+- The renderer build directory is no longer deleted before the renderer is
+  run. This allows a backend to cache results between runs.
+  [#985](https://github.com/rust-lang/mdBook/pull/985)
+- Next/prev links now highlight on hover to indicate it is clickable.
+  [#994](https://github.com/rust-lang/mdBook/pull/994)
+- Increase padding of table headers.
+  [#824](https://github.com/rust-lang/mdBook/pull/824)
+- Errors in `[output.html]` config are no longer ignored.
+  [#1033](https://github.com/rust-lang/mdBook/pull/1033)
+- Updated highlight.js for syntax highlighting updates (primarily to add
+  async/await to Rust highlighting).
+  [#1041](https://github.com/rust-lang/mdBook/pull/1041)
+- Raised minimum supported rust version to 1.35.
+  [#1003](https://github.com/rust-lang/mdBook/pull/1003)
+- Hidden code lines are no longer dynamically removed via JavaScript, but
+  instead managed with CSS.
+  [#846](https://github.com/rust-lang/mdBook/pull/846)
+  [#1065](https://github.com/rust-lang/mdBook/pull/1065)
+- Changed the default font set for the ACE editor, giving preference to
+  "Source Code Pro".
+  [#1062](https://github.com/rust-lang/mdBook/pull/1062)
+- Windows 32-bit releases are no longer published.
+  [#1071](https://github.com/rust-lang/mdBook/pull/1071)
+
+### Fixed
+- Fixed sidebar auto-scrolling.
+  [#1052](https://github.com/rust-lang/mdBook/pull/1052)
+- Fixed error message when running `clean` multiple times.
+  [#1055](https://github.com/rust-lang/mdBook/pull/1055)
+- Actually fix the "next" link on index.html. The previous fix didn't work.
+  [#1005](https://github.com/rust-lang/mdBook/pull/1005)
+- Stop using `inline-block` for `inline code`, fixing selection highlighting
+  and some rendering issues.
+  [#1058](https://github.com/rust-lang/mdBook/pull/1058)
+- Fix header auto-hide on browsers with momentum scrolling that allows
+  negative `scrollTop`.
+  [#1070](https://github.com/rust-lang/mdBook/pull/1070)
+
+## mdBook 0.3.1
+[69a08ef...9cd47eb](https://github.com/rust-lang/mdBook/compare/69a08ef...9cd47eb)
+
+### Added
+- 🔥 Added ability to include files using anchor points instead of line numbers.
+  [#851](https://github.com/rust-lang/mdBook/pull/851)
+- Added `language` configuration value to set the language of the book, which
+  will affect things like the `<html lang="en">` tag.
+  [#941](https://github.com/rust-lang/mdBook/pull/941)
+
+### Changed
+- Updated to handlebars 2.0.
+  [#977](https://github.com/rust-lang/mdBook/pull/977)
+
+### Fixed
+- Fixed memory leak warning.
+  [#967](https://github.com/rust-lang/mdBook/pull/967)
+- Fix more print.html links.
+  [#963](https://github.com/rust-lang/mdBook/pull/963)
+- Fixed crash on some unicode input.
+  [#978](https://github.com/rust-lang/mdBook/pull/978)
+
+## mdBook 0.3.0
+[6cbc41d...69a08ef](https://github.com/rust-lang/mdBook/compare/6cbc41d...69a08ef)
+
+### Added
+- Added ability to resize the sidebar.
+  [#849](https://github.com/rust-lang/mdBook/pull/849)
+- Added `load_with_config_and_summary` function to `MDBook` to be able to
+  build a book with a custom `Summary`.
+  [#883](https://github.com/rust-lang/mdBook/pull/883)
+- Set `noindex` on `print.html` page to prevent robots from indexing it.
+  [#844](https://github.com/rust-lang/mdBook/pull/844)
+- Added support for ~~strikethrough~~ and GitHub-style tasklists.
+  [#952](https://github.com/rust-lang/mdBook/pull/952)
+
+### Changed
+- Command-line help output is now colored.
+  [#861](https://github.com/rust-lang/mdBook/pull/861)
+- The build directory is now deleted before rendering starts, instead of after
+  if finishes.
+  [#878](https://github.com/rust-lang/mdBook/pull/878)
+- Removed dependency on `same-file` crate.
+  [#903](https://github.com/rust-lang/mdBook/pull/903)
+- 💥 Renamed `with_preprecessor` to `with_preprocessor`.
+  [#906](https://github.com/rust-lang/mdBook/pull/906)
+- Updated ACE editor to 1.4.4, should remove a JavaScript console warning.
+  [#935](https://github.com/rust-lang/mdBook/pull/935)
+- Dependencies have been updated.
+  [#934](https://github.com/rust-lang/mdBook/pull/934)
+  [#945](https://github.com/rust-lang/mdBook/pull/945)
+- Highlight.js has been updated. This fixes some TOML highlighting, and adds
+  Julia support.
+  [#942](https://github.com/rust-lang/mdBook/pull/942)
+- 🔥 Updated to pulldown-cmark 0.5. This may have significant changes to the
+  formatting of existing books, as the newer version has more accurate
+  interpretation of the CommonMark spec and a large number of bug fixes and
+  changes.
+  [#898](https://github.com/rust-lang/mdBook/pull/898)
+- The `diff` language should now highlight correctly.
+  [#943](https://github.com/rust-lang/mdBook/pull/943)
+- Make the blank region of a header not clickable.
+  [#948](https://github.com/rust-lang/mdBook/pull/948)
+- Rustdoc tests now use the preprocessed content instead of the raw,
+  unpreprocessed content.
+  [#891](https://github.com/rust-lang/mdBook/pull/891)
+
+### Fixed
+- Fixed file change detection so that `mdbook serve` only reloads once when
+  multiple files are changed at once.
+  [#870](https://github.com/rust-lang/mdBook/pull/870)
+- Fixed on-hover color highlighting for links in sidebar.
+  [#834](https://github.com/rust-lang/mdBook/pull/834)
+- Fixed loss of focus when clicking the "Copy" button in code blocks.
+  [#867](https://github.com/rust-lang/mdBook/pull/867)
+- Fixed incorrectly stripping the path for `additional-js` files.
+  [#796](https://github.com/rust-lang/mdBook/pull/796)
+- Fixed color of `code spans` that are links.
+  [#905](https://github.com/rust-lang/mdBook/pull/905)
+- Fixed "next" navigation on index.html.
+  [#916](https://github.com/rust-lang/mdBook/pull/916)
+- Fixed keyboard chapter navigation for `file` urls.
+  [#915](https://github.com/rust-lang/mdBook/pull/915)
+- Fixed bad wrapping for inline code on some browsers.
+  [#818](https://github.com/rust-lang/mdBook/pull/818)
+- Properly load an existing `SUMMARY.md` in `mdbook init`.
+  [#841](https://github.com/rust-lang/mdBook/pull/841)
+- Fixed some broken links in `print.html`.
+  [#871](https://github.com/rust-lang/mdBook/pull/871)
+- The Rust Playground link now supports the 2018 edition.
+  [#946](https://github.com/rust-lang/mdBook/pull/946)
+
+## mdBook 0.2.3 (2018-01-18)
+[2c20c99...6cbc41d](https://github.com/rust-lang/mdBook/compare/2c20c99...6cbc41d)
+
+### Added
+- Added an optional button to the top of the page which will link to a git
+  repository. Use the `git-repository-url` and `git-repository-icon` options
+  in the `[output.html]` section to enable it and set its appearance.
+  [#802](https://github.com/rust-lang/mdBook/pull/802)
+- Added a `default-theme` option to the `[output.html]` section.
+  [#804](https://github.com/rust-lang/mdBook/pull/804)
+
+### Changed
+- 💥 Header ID anchors no longer add an arbitrary `a` character for headers
+  that start with a non-ascii-alphabetic character.
+  [#788](https://github.com/rust-lang/mdBook/pull/788)
+
+### Fixed
+- Fix websocket hostname usage
+  [#865](https://github.com/rust-lang/mdBook/pull/865)
+- Fixing links in print.html
+  [#866](https://github.com/rust-lang/mdBook/pull/866)
+
+## mdBook 0.2.2 (2018-10-19)
+[7e2e095...2c20c99](https://github.com/rust-lang/mdBook/compare/7e2e095...2c20c99)
+
+### Added
+- 🎉 Process-based custom preprocessors. See [the
+  docs](https://rust-lang.github.io/mdBook/for_developers/preprocessors.html)
+  for more.
+  [#792](https://github.com/rust-lang/mdBook/pull/792)
+
+- 🎉 Configurable preprocessors.
+
+  Added `build.use-default-preprocessors` boolean TOML key to allow disabling
+  the built-in `links` and `index` preprocessors.
+
+  Added `[preprocessor]` TOML tables to configure each preprocessor.
+
+  Specifying `[preprocessor.links]` or `[preprocessor.index]` will enable the
+  respective built-in preprocessor if `build.use-default-preprocessors` is
+  `false`.
+
+  Added `fn supports_renderer(&self, renderer: &str) -> bool` to the
+  `Preprocessor` trait to specify if the preprocessor supports the given
+  renderer. The default implementation always returns `true`.
+
+  `Preprocessor::run` now takes a book by value instead of a mutable
+  reference. It should return a `Book` value with the intended modifications.
+
+  Added `PreprocessorContext::renderer` to indicate the renderer being used.
+
+  [#658](https://github.com/rust-lang/mdBook/pull/658)
+  [#787](https://github.com/rust-lang/mdBook/pull/787)
+
+### Fixed
+- Fix paths to additional CSS and JavaScript files
+  [#777](https://github.com/rust-lang/mdBook/pull/777)
+- Ensure section numbers are correctly incremented after a horizontal
+  separator
+  [#790](https://github.com/rust-lang/mdBook/pull/790)
+
+## mdBook 0.2.1 (2018-08-22)
+[91ffca1...7e2e095](https://github.com/rust-lang/mdBook/compare/91ffca1...7e2e095)
+
+### Changed
+- Update to handlebars-rs 1.0
+  [#761](https://github.com/rust-lang/mdBook/pull/761)
+
+### Fixed
+- Fix table colors, broken by Stylus -> CSS transition
+  [#765](https://github.com/rust-lang/mdBook/pull/765)
+
+## mdBook 0.2.0 (2018-08-02)
+
+### Changed
+- 💥 This release changes how links are handled in mdBook. Previously, relative
+  links were interpreted relative to the book's root. In `0.2.0`+ links are
+  relative to the page they are in, and use the `.md` extension. This has [several
+  advantages](https://github.com/rust-lang/mdBook/pull/603#issue-166701447),
+  such as making links work in other markdown viewers like GitHub. You will
+  likely have to change links in your book to accommodate this change. For
+  example, a book with this layout:
+
+  ```
+  chapter_1/
+      section_1.md
+      section_2.md
+  SUMMARY.md
+  ```
+
+  Previously a link in `section_1.md` to `section_2.md` would look like this:
+  ```markdown
+  [section_2](chapter_1/section_2.html)
+  ```
+
+  Now it must be changed to this:
+  ```markdown
+  [section_2](section_2.md)
+  ```
+
+- 💥 `mdbook test --library-path` now accepts a comma-delimited list of
+  arguments rather than taking all following arguments. This makes it easier
+  to handle the trailing book directory argument without always needing to put
+  ` -- ` before it. Multiple instances of the option continue to be accepted:
+  `mdbook test -L foo -L bar`.
+
+- 💥 `mdbook serve` has some of its options renamed for clarity. See `mdbook
+  help serve` for details.
+
+- Embedded rust playpens now use the "stable" playground API.
+  [#754](https://github.com/rust-lang/mdBook/pull/754)
+
+### Fixed
+- Escaped includes (`\{{#include file.rs}}`) will now render correctly.
+  [f30ce01](https://github.com/rust-lang/mdBook/commit/f30ce0184d71e342141145472bf816419d30a2c5)
+- `index.html` will now render correctly when the book's first section is
+  inside a subdirectory.
+  [#756](https://github.com/rust-lang/mdBook/pull/756)

CODE_OF_CONDUCT.md

@@ -0,0 +1,3 @@
+# The Rust Code of Conduct
+
+The Code of Conduct for this repository [can be found online](https://www.rust-lang.org/conduct.html).

CONTRIBUTING.md

@@ -0,0 +1,155 @@
+# Contributing
+
+Welcome stranger!
+
+If you have come here to learn how to contribute to mdBook, we have some tips for you!
+
+First of all, don't hesitate to ask questions!
+Use the [issue tracker](https://github.com/rust-lang/mdBook/issues), no question is too simple.
+
+### Issue assignment
+
+**:warning: Important :warning:**
+
+Before working on pull request, please ping us on the corresponding issue.
+The current PR backlog is beyond what we can process at this time.
+Only issues that have an [`E-Help-wanted`](https://github.com/rust-lang/mdBook/labels/E-Help-wanted) or [`Feature accepted`](https://github.com/rust-lang/mdBook/labels/Feature%20accepted) label will likely receive reviews.
+If there isn't already an open issue for what you want to work on, please open one first to see if it is something we would be available to review.
+
+### Issues to work on
+
+If you are starting out, you might be interested in the
+[E-Easy issues](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AE-Easy).
+Those are issues that are considered more straightforward for beginners to Rust or the codebase itself.
+These issues can be a good launching pad for more involved issues.
+Easy tasks for a first time contribution include documentation improvements, new tests, examples, updating dependencies, etc.
+
+If you come from a web development background, you might be interested in issues related to web technologies tagged
+[A-JavaScript](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-JavaScript),
+[A-Style](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Style),
+[A-HTML](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-HTML) or
+[A-Mobile](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Mobile).
+
+When you decide you want to work on a specific issue, and it isn't already assigned to someone else, assign the issue to yourself by leaving a comment with the text `@rustbot claim`.
+Again, do not hesitate to ask questions. We will gladly mentor anyone that want to tackle an issue.
+
+Issues on the issue tracker are categorized with the following labels:
+
+- **A**-prefixed labels state which area of the project an issue relates to.
+- **E**-prefixed labels show an estimate of the experience necessary to fix the issue.
+- **M**-prefixed labels are meta-issues regarding the management of the mdBook project itself
+- **S**-prefixed labels show the status of the issue
+- **C**-prefixed labels show the category of issue
+
+### Building mdBook
+
+mdBook builds on stable Rust, if you want to build mdBook from source, here are the steps to follow:
+
+1. Navigate to the directory of your choice
+0. Clone this repository with git.
+
+   ```
+   git clone https://github.com/rust-lang/mdBook.git
+   ```
+0. Navigate into the newly created `mdBook` directory
+0. Run `cargo build`
+
+The resulting binary can be found in `mdBook/target/debug/` under the name `mdbook` or `mdbook.exe`.
+
+### Code Quality
+
+We love code quality and Rust has some excellent tools to assist you with contributions.
+
+#### Formatting Code with rustfmt
+
+Before you make your Pull Request to the project, please run it through the `rustfmt` utility.
+This will ensure we have good quality source code that is better for us all to maintain.
+
+[rustfmt](https://github.com/rust-lang/rustfmt) has a lot more information on the project.
+The quick guide is
+
+1. Install it (`rustfmt` is usually installed by default via [rustup](https://rustup.rs/)):
+    ```
+    rustup component add rustfmt
+    ```
+1. You can now run `rustfmt` on a single file simply by...
+    ```
+    rustfmt src/path/to/your/file.rs
+    ```
+   ... or you can format the entire project with
+   ```
+   cargo fmt
+   ```
+   When run through `cargo` it will format all bin and lib files in the current package.
+
+For more information, such as running it from your favourite editor, please see the `rustfmt` project. [rustfmt](https://github.com/rust-lang/rustfmt)
+
+
+#### Finding Issues with Clippy
+
+[Clippy](https://doc.rust-lang.org/clippy/) is a code analyser/linter detecting mistakes, and therefore helps to improve your code.
+Like formatting your code with `rustfmt`, running clippy regularly and before your Pull Request will help us maintain awesome code.
+
+1. To install
+    ```
+    rustup component add clippy
+    ```
+2. Running clippy
+    ```
+    cargo clippy
+    ```
+
+### Change requirements
+
+Please consider the following when making a change:
+
+* Almost all changes that modify the Rust code must be accompanied with a test.
+
+* Almost all features and changes must update the documentation.
+  mdBook has the [mdBook Guide](https://rust-lang.github.io/mdBook/) whose source is at <https://github.com/rust-lang/mdBook/tree/master/guide>.
+
+* Almost all Rust items should be documented with doc comments.
+  See the [Rustdoc Book](https://doc.rust-lang.org/rustdoc/) for more information on writing doc comments.
+
+* Breaking the API can only be done in major SemVer releases.
+  These are done very infrequently, so it is preferred to avoid these when possible.
+  See [SemVer Compatibility](https://doc.rust-lang.org/cargo/reference/semver.html) for more information on what a SemVer breaking change is.
+
+  (Note: At this time, some SemVer breaking changes are inevitable due to the current code structure.
+  An example is adding new fields to the config structures.
+  These are intended to be fixed in the next major release.)
+
+* Similarly, the CLI interface is considered to be stable.
+  Care should be taken to avoid breaking existing workflows.
+
+* Check out the [Rust API Guidelines](https://rust-lang.github.io/api-guidelines/) for guidelines on designing the API.
+
+### Making a pull-request
+
+When you feel comfortable that your changes could be integrated into mdBook, you can create a pull-request on GitHub.
+One of the core maintainers will then approve the changes or request some changes before it gets merged.
+
+That's it, happy contributions! :tada: :tada: :tada:
+
+## Browser compatibility and testing
+
+Currently we don't have a strict browser compatibility matrix due to our limited resources.
+We generally strive to keep mdBook compatible with a relatively recent browser on all of the most major platforms.
+That is, supporting Chrome, Safari, Firefox, Edge on Windows, macOS, Linux, iOS, and Android.
+If possible, do your best to avoid breaking older browser releases.
+
+Any change to the HTML or styling is encouraged to manually check on as many browsers and platforms that you can.
+Unfortunately at this time we don't have any automated UI or browser testing, so your assistance in testing is appreciated.
+
+## Updating highlight.js
+
+The following are instructions for updating [highlight.js](https://highlightjs.org/).
+
+1. Clone the repository at <https://github.com/highlightjs/highlight.js>
+1. Check out a tagged release (like `10.1.1`).
+1. Run `npm install`
+1. Run `node tools/build.js :common apache armasm coffeescript d handlebars haskell http julia nginx properties r scala x86asm yaml`
+1. Compare the language list that it spits out to the one in [`syntax-highlighting.md`](https://github.com/camelid/mdBook/blob/master/guide/src/format/theme/syntax-highlighting.md). If any are missing, add them to the list and rebuild (and update these docs). If any are added to the common set, add them to `syntax-highlighting.md`.
+1. Copy `build/highlight.min.js` to mdbook's directory [`highlight.js`](https://github.com/rust-lang/mdBook/blob/master/src/theme/highlight.js).
+1. Be sure to check the highlight.js [CHANGES](https://github.com/highlightjs/highlight.js/blob/main/CHANGES.md) for any breaking changes. Breaking changes that would affect users will need to wait until the next major release.
+1. Build mdbook with the new file and build some books with the new version and compare the output with a variety of languages to see if anything changes. The [test_book](https://github.com/rust-lang/mdBook/tree/master/test_book) contains a chapter with many languages to examine.

Cargo.toml

@@ -1,44 +1,73 @@
 [package]
 name = "mdbook"
-version = "0.0.8"
-authors = ["Mathieu David <mathieudavid@mathieudavid.org>"]
-description = "create books from markdown files (like Gitbook)"
-documentation = "http://azerupi.github.io/mdBook/index.html"
-repository = "https://github.com/azerupi/mdBook"
+version = "0.4.26"
+authors = [
+    "Mathieu David <mathieudavid@mathieudavid.org>",
+    "Michael-F-Bryan <michaelfbryan@gmail.com>",
+    "Matt Ickstadt <mattico8@gmail.com>"
+]
+documentation = "https://rust-lang.github.io/mdBook/index.html"
+edition = "2021"
+exclude = ["/guide/*"]
 keywords = ["book", "gitbook", "rustbook", "markdown"]
 license = "MPL-2.0"
 readme = "README.md"
-build = "build.rs"
-exclude = [
-    "book-example/*",
-    "src/theme/stylus",
-]
+repository = "https://github.com/rust-lang/mdBook"
+description = "Creates a book from markdown files"
+rust-version = "1.60"
 
 [dependencies]
-clap = "~1.5.3"
-handlebars = "~0.12.0"
-rustc-serialize = "~0.3.16"
-pulldown-cmark = "~0.0.6"
+anyhow = "1.0.28"
+chrono = { version = "0.4", default-features = false, features = ["clock"] }
+clap = { version = "4.0.29", features = ["cargo", "wrap_help"] }
+clap_complete = "4.0.6"
+once_cell = "1"
+env_logger = "0.10.0"
+handlebars = "4.0"
+log = "0.4"
+memchr = "2.0"
+opener = "0.5"
+pulldown-cmark = { version = "0.9.1", default-features = false }
+regex = "1.5.5"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+shlex = "1"
+tempfile = "3.0"
+toml = "0.7.2"
+topological-sort = "0.2.2"
 
 # Watch feature
-notify = { version = "~2.4.1", optional = true }
-time = { version = "~0.1.33", optional = true }
-crossbeam = { version = "~0.2.8", optional = true }
+notify = { version = "5.0.0", optional = true }
+notify-debouncer-mini = { version = "0.2.1", optional = true }
+gitignore = { version = "1.0", optional = true }
 
+# Serve feature
+futures-util = { version = "0.3.4", optional = true }
+tokio = { version = "1", features = ["macros", "rt-multi-thread"], optional = true }
+warp = { version = "0.3.2", default-features = false, features = ["websocket"], optional = true }
+
+# Search feature
+elasticlunr-rs = { version = "3.0.0", optional = true }
+ammonia = { version = "3", optional = true }
 
-# Tests
 [dev-dependencies]
-tempdir = "~0.3.4"
-
+assert_cmd = "2.0.7"
+predicates = "2"
+select = "0.6.0"
+semver = "1.0"
+pretty_assertions = "1.2.1"
+walkdir = "2.0"
 
 [features]
-default = ["output", "watch"]
-debug = []
-output = []
-regenerate-css = []
-watch = ["notify", "time", "crossbeam"]
+default = ["watch", "serve", "search"]
+watch = ["notify", "notify-debouncer-mini", "gitignore"]
+serve = ["futures-util", "tokio", "warp"]
+search = ["elasticlunr-rs", "ammonia"]
 
 [[bin]]
 doc = false
 name = "mdbook"
-path = "src/bin/mdbook.rs"
+
+[[example]]
+name = "nop-preprocessor"
+test = true

README.md

@@ -1,93 +1,20 @@
-# mdBook [![Travis-CI](https://travis-ci.org/azerupi/mdBook.svg?branch=master)](https://travis-ci.org/azerupi/mdBook) [![Crates.io version](https://img.shields.io/crates/v/mdbook.svg)](https://crates.io/crates/mdbook) [![License](https://img.shields.io/crates/l/mdbook.svg)](LICENSE)
+# mdBook
 
-mdBook is a utility to create modern online books from markdown files.
+[![Build Status](https://github.com/rust-lang/mdBook/workflows/CI/badge.svg?event=push)](https://github.com/rust-lang/mdBook/actions?workflow=CI)
+[![crates.io](https://img.shields.io/crates/v/mdbook.svg)](https://crates.io/crates/mdbook)
+[![LICENSE](https://img.shields.io/github/license/rust-lang/mdBook.svg)](LICENSE)
 
-**This project is still in its early days.**
-For more information about what is left on my to-do list, check the issue tracker
+mdBook is a utility to create modern online books from Markdown files.
 
+Check out the **[User Guide]** for a list of features and installation and usage information.
+The User Guide also serves as a demonstration to showcase what a book looks like.
 
-## What does it look like?
-
-The [**Documentation**](http://azerupi.github.io/mdBook/) for mdBook has been written in markdown and is using mdBook to generate the online book-like website you can read. The documentation uses the latest version on github and showcases the available features.
-
-## Installation
-
-There are 2 ways to install mdBook but both require [Rust and Cargo](https://www.rust-lang.org/) to be installed.
-
-##### Install from Crates.io
-
-Once you have installed Rust, type the following in the terminal:
-```
-cargo install mdbook
-```
-
-This will download and compile mdBook for you, the only thing you that will be left to do is add the Cargo bin directory to your path.
-
-##### Install from git
-
-The version published to Crates.io will ever so slightly be behind the version hosted here on Github. If you need the latest version you can build the git version of mdBook yourself. Cargo makes this ***super easy***!
-
-First, clone the repository on your computer:
-
-```
-git clone --depth 1 https://github.com/azerupi/mdBook.git
-```
-
-Then `cd` into the directory and run:
-
-```
-cargo build --release
-```
-
-The executable will be in `./target/release/mdbook`.
-
-
-
-## Usage
-
-mdBook will primaraly be used as a command line tool, even though it exposes all its functionality as a Rust crate for integration in other projects.
-
-Here are the main commands you will want to run, for a more exhaustive explanation, check out the [documentation](http://azerupi.github.io/mdBook/).
-
-- `mdbook init`
-
-    The init command will create a directory with the minimal boilerplate to start with.
-
-    ```
-    book-test/
-    ├── book
-    └── src
-        ├── chapter_1.md
-        └── SUMMARY.md
-    ```
-
-    `book` and `src` are both directories. `src` contains the markdown files that will be used to render the ouput to the `book` directory.
-
-    Please, take a look at the [**Documentation**](http://azerupi.github.io/mdBook/cli/init.html) for more information and some neat tricks.
-
-- `mdbook build`
-
-    This is the command you will run to render your book, it reads the `SUMMARY.md` file to understand the structure of your book, takes the markdown files in the source directory as input and outputs static html pages that you can upload to a server.
-
-- `mdbook watch`
-
-    When you run this command, mdbook will watch your markdown files to rebuild the book on every change. This avoids having to come back to the terminal to type `mdbook build` over and over again.
-
-### As a library
-
-Aside from the command line interface, this crate can also be used as a library. This means that you could integrate it in an existing project, like a web-app for example. Since the command line interface is just a wrapper around the library functionality, when you use this crate as a library you have full access to all the functionality of the command line interface with and easy to use API and more!
-
-See the [Documentation](http://azerupi.github.io/mdBook/lib/lib.html) and the [API docs](http://azerupi.github.io/mdBook/mdbook/index.html) for more information.
-
-## Contributions
-
-Contributions are highly appreciated and encouraged! Don't hesitate to participate to discussions in the issues, propose new features and ask for help.
-
-People who are not familiar with the code can look at [issues that are tagged **easy**](https://github.com/azerupi/mdBook/labels/Easy). A lot of issues are also related to web development, so people that are not comfortable with Rust can also participate! :wink:
-
-You can pick any issue you want to work on. Usually it's a good idea to ask if someone is already working on it and if not to claim the issue.
-
+If you are interested in contributing to the development of mdBook, check out the [Contribution Guide].
 
 ## License
 
-All the code is released under the ***Mozilla Public License v2.0***, for more information take a look at the [LICENSE](LICENSE) file
+All the code in this repository is released under the ***Mozilla Public License v2.0***, for more information take a look at the [LICENSE] file.
+
+[User Guide]: https://rust-lang.github.io/mdBook/
+[contribution guide]: https://github.com/rust-lang/mdBook/blob/master/CONTRIBUTING.md
+[LICENSE]: https://github.com/rust-lang/mdBook/blob/master/LICENSE

book-example/book.json

@@ -1,4 +0,0 @@
-{
-    "title": "mdBook Documentation",
-    "author": "Mathieu David"
-}

book-example/src/README.md

@@ -1,16 +0,0 @@
-# mdBook
-
-**mdBook** is a command line tool and Rust crate to create books using Markdown files. It's very similar to Gitbook but written in [Rust](http://www.rust-lang.org).
-
-What you are reading serves as an example of the output of mdBook and at the same time as high-level docs.
-
-mdBook is free and open source, you can find the source code on [Github](https://github.com/azerupi/mdBook). Issues and feature requests can be posted on the [Github Issue tracker](https://github.com/azerupi/mdBook/issues).
-
-## API docs
-
-Alongside this book you can also read the [API docs](mdbook/index.html) generated by Rustdoc if you would like
-to use mdBook as a crate or write a new renderer and need a more low-level overview.
-
-## License
-
-mdBook, all the source code, is released under the [Mozilla Public License v2.0](https://www.mozilla.org/MPL/2.0/)

book-example/src/cli/build.md

@@ -1,26 +0,0 @@
-# The build command
-
-The build command is used to render your book:
-
-```bash
-mdbook build
-```
-
-It will try to parse your `SUMMARY.md` file to understand the structure of your book
-and fetch the corresponding files.
-
-The rendered output will maintain the same directory structure as the source for
-convenience. Large books will therefore remain structured when rendered.
-
-#### Specify a directory
-
-Like `init`, the `build` command can take a directory as argument to use instead of the
-current working directory.
-
-```bash
-mdbook build path/to/book
-```
-
--------------------
-
-***note:*** *make sure to run the build command in the root directory and not in the source directory*

book-example/src/cli/cli-tool.md

@@ -1,35 +0,0 @@
-# Command Line Tool
-
-mdBook can be used either as a command line tool or a [Rust crate](https://crates.io/crates/mdbook).
-Let's focus on the command line tool capabilities first.
-
-## Install
-
-### Pre-requisite
-
-mdBook is written in **[Rust](https://www.rust-lang.org/)** and therefore needs to be compiled with **Cargo**, because we don't yet offer ready-to-go binaries. If you haven't already installed Rust, please go ahead and [install it](https://www.rust-lang.org/downloads.html) now.
-
-### Install Crates.io version
-
-Installing mdBook is relatively easy if you already have Rust and Cargo installed. You just have to type this snippet in your terminal:
-
-```bash
-cargo install mdbook
-```
-
-This will fetch the source code from [Crates.io](https://crates.io/) and compile it. You will have to add Cargo's `bin` directory to your `PATH`.
-
-Run `mdbook help` in your terminal to verify if it works. Congratulations, you have installed mdBook!
-
-
-### Install Git version
-
-The **[git version](https://github.com/azerupi/mdBook)** contains all the latest bug-fixes and features, that will be released in the next version on **Crates.io**, if you can't wait until the next release. You can build the git version yourself. Open your terminal and navigate to the directory of you choice. We need to clone the git repository and then build it with Cargo.
-
-```bash
-git clone --depth=1 https://github.com/azerupi/mdBook.git
-cd mdBook
-cargo build --release
-```
-
-The executable `mdbook` will be in the `./target/release` folder, this should be added to the path.

book-example/src/cli/init.md

@@ -1,45 +0,0 @@
-# The init command
-There is some minimal boilerplate that is the same for every new book. It's for this purpose that mdBook includes an `init` command.
-
-The `init` command is used like this:
-
-```bash
-mdbook init
-```
-
-When using the `init` command for the first time, a couple of files will be set up for you:
-```bash
-book-test/
-├── book
-└── src
-    ├── chapter_1.md
-    └── SUMMARY.md
-```
-
-- The `src` directory is were you write your book in markdown. It contains all the source files,
-configuration files, etc.
-
-- The `book` directory is where your book is rendered. All the output is ready to be uploaded
-to a server to be seen by your audience.
-
-- The `SUMMARY.md` file is the most important file, it's the skeleton of your book and is discussed in more detail in another  [chapter](../format/summary.html).
-
-#### Tip & Trick: Hidden Feature
-When a `SUMMARY.md` file already exists, the `init` command will first parse it and generate the missing files according to the paths used in the `SUMMARY.md`. This allows you to think and create the whole structure of your book and then let mdBook generate it for you.
-
-#### Specify a directory
-
-When using the `init` command, you can also specify a directory, instead of using the current working directory,
-by appending a path to the command:
-
-```bash
-mdbook init path/to/book
-```
-
-## --theme
-
-When you use the `--theme` argument, the default theme will be copied into a directory
-called `theme` in your source directory so that you can modify it.
-
-The theme is selectively overwritten, this means that if you don't want to overwrite a
-specific file, just delete it and the default file will be used.

book-example/src/cli/test.md

@@ -1,19 +0,0 @@
-# The test command
-
-When writing a book, you sometimes need to automate some tests. For example, [The Rust Programming Book](https://doc.rust-lang.org/stable/book/) uses a lot of code examples that could get outdated.
-Therefore it is very important for them to be able to automatically test these code examples.
-
-mdBook supports a `test` command that will run all available tests in mdBook. At the moment, only one test is available:
-*"Test Rust code examples using Rustdoc"*, but I hope this will be expanded in the future to include more tests like:
-
-- checking for broken links
-- checking for unused files
-- ...
-
-In the future I would like the user to be able to enable / disable test from the `book.json` configuration file and support custom tests.
-
-**How to use it:**
-```bash
-$ mdbook test
-[*]: Testing file: "/mdBook/book-example/src/README.md”
-```

book-example/src/cli/watch.md

@@ -1,18 +0,0 @@
-# The watch command
-
-The `watch` command is useful when you want your book to be rendered on every file change.
-You could repeatedly issue `mdbook build` every time a file is changed. But using `mdbook watch` once will watch your files and will trigger a build automatically whenever you modify a file.
-
-#### Specify a directory
-
-Like `init` and `build`, `watch` can take a directory as argument to use instead of the
-current working directory.
-
-```bash
-mdbook watch path/to/book
-```
-
-
------
-
-***note:*** *the `watch` command has not gotten a lot of testing yet, there could be some rough edges. If you discover a problem, please report it [on Github](https://github.com/azerupi/mdBook/issues)*

book-example/src/format/config.md

@@ -1,21 +0,0 @@
-# Configuration
-
-You can configure the parameters for your book in the ***book.json*** file.
-
-Here is an example of what a ***book.json*** file might look like:
-
-```json
-{
-    "title": "Example book",
-    "author": "Name",
-    "dest": "output/my-book"
-}
-```
-
-#### Supported variables
-
-- **title:** title of the book
-- **author:** author of the book
-- **dest:** path to the directory where you want your book to be rendered. If a relative path is given it will be relative to the parent directory of the source directory
-
-***note:*** *the supported configurable parameters are scarce at the moment, but more will be added in the future*

book-example/src/format/mathjax.md

@@ -1,21 +0,0 @@
-# MathJax Support
-
-mdBook supports math equations through [MathJax](https://www.mathjax.org/).
-
-**However the normal method for indication math equations with `$$` does not work (yet?).**
-
-To indicate an inline equation \\( \int x = \frac{x^2}{2} \\) use
-```
-\\( \int x = \frac{x^2}{2} \\)
-```
-
-To indicate a block equation
-
-\\[ \mu = \frac{1}{N} \sum_{i=0} x_i \\]
-
-
-use
-
-```
-\\[ \mu = \frac{1}{N} \sum_{i=0} x_i \\]
-```

book-example/src/format/rust.md

@@ -1,42 +0,0 @@
-# Rust code specific features
-
-## Hiding code lines
-
-There is a feature in mdBook that let's you hide code lines by prepending them with a `#`.
-
-```bash
-#fn main() {
-    let x = 5;
-    let y = 6;
-
-    println!("{}", x + y);
-#}
-```
-
-Will render as
-
-```rust
-#fn main() {
-    let x = 5;
-    let y = 7;
-
-    println!("{}", x + y);
-#}
-```
-
-
-## Inserting runnable Rust files
-
-With the following syntax, you can insert runnable Rust files into your book:
-
-```hbs
-\{{#playpen file.rs}}
-```
-
-The path to the Rust file has to be relative from the current source file.
-
-When play is clicked, the code snippet will be send to the [Rust Playpen]() to be compiled and run. The result is send back and displayed directly underneath the code.
-
-Here is what a rendered code snippet looks like:
-
-{{#playpen example.rs}}

book-example/src/format/summary.md

@@ -1,32 +0,0 @@
-# SUMMARY.md
-
-The summary file is used by mdBook to know what chapters to include,
-in what order they should appear, what their hierarchy is and where the source files are.
-Without this file, there is no book.
-
-Even though `SUMMARY.md` is a markdown file, the formatting is very strict to
-allow for easy parsing. Let's see how you should format your `SUMMARY.md` file.
-
-#### Allowed elements
-
-1. ***Title*** It's common practice to begin with a title, generally
-   <code class="language-markdown"># Summary</code>.
-   But it is not mandatory, the parser just ignores it. So you can too
-   if you feel like it.
-
-2. ***Prefix Chapter*** Before the main numbered chapters you can add a couple of elements that will not be numbered. This is useful for
-   forewords, introductions, etc. There are however some constraints. You can not nest prefix chapters, they should all be on the root level. And you can not add prefix chapters once you have added numbered chapters.
-   ```markdown
-   [Title of prefix element](relative/path/to/markdown.md)
-   ```
-
-3. ***Numbered Chapter*** Numbered chapters are the main content of the book, they will be numbered and can be nested,
-   resulting in a nice hierarchy (chapters, sub-chapters, etc.)
-   ```markdown
-   - [Title of the Chapter](relative/path/to/markdown.md)
-   ```
-   You can either use `-` or `*` to indicate a numbered chapter.
-
-4. ***Sufix Chapter*** After the numbered chapters you can add a couple of non-numbered chapters. They are the same as prefix chapters but come after the numbered chapters instead of before.
-
-All other elements are unsupported and will be ignored at best or result in an error.

book-example/src/format/theme/index-hbs.md

@@ -1,90 +0,0 @@
-# index.hbs
-
-`index.hbs` is the handlebars template that is used to render the book.
-The markdown files are processed to html and then injected in that template.
-
-If you want to change the layout or style of your book, chances are that you will
-have to modify this template a little bit. Here is what you need to know.
-
-## Data
-
-A lot of data is exposed to the handlebars template with the "context".
-In the handlebars template you can access this information by using
-
-```handlebars
-{{name_of_property}}
-```
-
-Here is a list of the properties that are exposed:
-
-- ***language*** Language of the book in the form `en`. To use in <code class="language-html">\<html lang="{{ language }}"></code> for example.
-At the moment it is hardcoded.
-- ***title*** Title of the book, as specified in `book.json`
-
-- ***path*** Relative path to the original markdown file from the source directory
-- ***content*** This is the rendered markdown.
-- ***path_to_root*** This is a path containing exclusively `../`'s that points to the root of the book from the current file.
-Since the original directory structure is maintained, it is useful to prepend relative links with this `path_to_root`.
-
-- ***chapters*** Is an array of dictionaries of the form
-  ```json
-  {"section": "1.2.1", "name": "name of this chapter", "path": "dir/markdown.md"}
-  ```
-  containing all the chapters of the book. It is used for example to construct the table of contents (sidebar).
-
-## Handlebars Helpers
-
-In addition to the properties you can access, there are some handlebars helpers at your disposal.
-
-1.  ### toc
-
-    The toc helper is used like this
-
-    ```handlebars
-    {{#toc}}{{/toc}}
-    ```
-
-    and outputs something that looks like this, depending on the structure of your book
-
-    ```html
-    <ul class="chapter">
-        <li><a href="link/to/file.html">Some chapter</a></li>
-        <li>
-            <ul class="section">
-                <li><a href="link/to/other_file.html">Some other Chapter</a></li>
-            </ul>
-        </li>
-    </ul>
-    ```
-
-    If you would like to make a toc with another structure, you have access to the chapters property containing all the data.
-    The only limitation at the moment is that you would have to do it with JavaScript instead of with a handlebars helper.
-
-    ```html
-    <script>
-    var chapters = {{chapters}};
-    // Processing here
-    </script>
-    ```
-
-2.  ### previous / next
-
-    The previous and next helpers expose a `link` and `name` property to the previous and next chapters.
-
-    They are used like this
-
-    ```handlebars
-    {{#previous}}
-        <a href="{{link}}" class="nav-chapters previous">
-            <i class="fa fa-angle-left"></i>
-        </a>
-    {{/previous}}
-    ```
-
-    The inner html will only be rendered if the previous / next chapter exists.
-    Of course the inner html can be changed to your liking.
-
-------
-
-*If you would like me to expose other properties or helpers, please [create a new issue](https://github.com/azerupi/mdBook/issues)
-and I will consider it.*

book-example/src/format/theme/syntax-highlighting.md

@@ -1,60 +0,0 @@
-# Syntax Highlighting
-
-For syntax highlighting I use [Highlight.js](https://highlightjs.org) with a custom theme.
-
-Automatic language detection has been turned off, so you will probably want to
-specify the programming language you use like this
-
-<pre><code class="language-markdown">```rust
-fn main() {
-    // Some code
-}
-```</code></pre>
-
-## Custom theme
-Like the rest of the theme, the files used for syntax highlighting can be overridden with your own.
-
-- ***highlight.js*** normally you shouldn't have to overwrite this file, unless you want to use a more recent version.
-- ***highlight.css*** theme used by highlight.js for syntax highlighting.
-
-If you want to use another theme for `highlight.js` download it from their website, or make it yourself,
-rename it to `highlight.css` and put it in `src/theme` (or the equivalent if you changed your source folder)
-
-Now your theme will be used instead of the default theme.
-
-## Hiding code lines
-
-There is a feature in mdBook that let's you hide code lines by prepending them with a `#`.
-
-
-```bash
-#fn main() {
-    let x = 5;
-    let y = 6;
-
-    println!("{}", x + y);
-#}
-```
-
-Will render as
-
-```rust
-#fn main() {
-    let x = 5;
-    let y = 7;
-
-    println!("{}", x + y);
-#}
-```
-
-**At the moment, this only works for code examples that are annotated with `rust`. Because it would collide with semantics of some programming languages. In the future, we want to make this configurable through the `book.json` so that everyone can benefit from it.**
-
-
-## Improve default theme
-
-If you think the default theme doesn't look quite right for a specific language, or could be improved.
-Feel free to [submit a new issue](https://github.com/azerupi/mdBook/issues) explaining what you have in mind and I will take a look at it.
-
-You could also create a pull-request with the proposed improvements.
-
-Overall the theme should be light and sober, without to many flashy colors.

book-example/src/format/theme/theme.md

@@ -1,21 +0,0 @@
-# Theme
-
-The default renderer uses a [handlebars](http://handlebarsjs.com/) template to render your markdown files and comes with a default theme
-included in the mdBook binary.
-
-The theme is totally customizable, you can selectively replace every file from the theme by your own by adding a
-`theme` directory in your source folder. Create a new file with the name of the file you want to override
-and now that file will be used instead of the default file.
-
-Here are the files you can override:
-
-- ***index.hbs*** is the handlebars template.
-- ***book.css*** is the style used in the output. If you want to change the design of your book, this is probably the file you want to modify. Sometimes in conjunction with `index.hbs` when you want to radically change the layout.
-- ***book.js*** is mostly used to add client side functionality, like hiding / un-hiding the sidebar, changing the theme, ...
-- ***highlight.js*** is the JavaScript that is used to highlight code snippets, you should not need to modify this.  
-- ***highlight.css*** is the theme used for the code highlighting
-
-Generally, when you want to tweak the theme, you don't need to override all the files. If you only need changes in the stylesheet,
-there is no point in overriding all the other files. Because custom files take precedence over built-in ones, they will not get updated with new fixes / features.
-
-**Note:** When you override a file, it is possible that you break some functionality. Therefore I recommend to use the file from the default theme as template and only add / modify what you need. You can copy the default theme into your source directory automatically by using `mdbook init --theme` just remove the files you don't want to override.

book-example/src/lib/lib.md

@@ -1,22 +0,0 @@
-# Rust Library
-
-mdBook is not only a command line tool, it can be used as a crate. You can extend it,
-integrate it in current projects. Here is a short example:
-
-```rust,ignore
-extern crate mdbook;
-
-use mdbook::MDBook;
-use std::path::Path;
-
-fn main() {
-    let mut book =  MDBook::new(Path::new("my-book"))   // Path to root
-                        .set_src(Path::new("src"))      // Path from root to source directory
-                        .set_dest(Path::new("book"))    // Path from root to output directory
-                        .read_config();                 // Parse book.json file for configuration
-
-    book.build().unwrap();                              // Render the book
-}
-```
-
-Check here for the [API docs](../mdbook/index.html) generated by rustdoc.

book-example/src/misc/contributors.md

@@ -1,13 +0,0 @@
-# Contributors
-
-Here is a list of the contributors who have helped improving mdBook. Big shout-out to them!
-
-If you have contributed to mdBook and I forgot to add you, don't hesitate to add yourself to the list. If you are in the list, feel free to add your real name & contact information if you wish.
-
-- [mdinger](https://github.com/mdinger)
-- Kevin ([kbknapp](https://github.com/kbknapp))
-- Steve Klabnik ([steveklabnik](https://github.com/steveklabnik))
-- Adam Solove ([asolove](https://github.com/asolove))
-- Wayne Nilsen ([waynenilsen](https://github.com/waynenilsen))
-- [funnkill](https://github.com/funkill)
-- Fu Gangqiang ([FuGangqiang](https://github.com/FuGangqiang))

build.rs

@@ -1,29 +0,0 @@
-// build.rs
-
-use std::process::Command;
-use std::env;
-use std::path::Path;
-
-fn main() {
-
-    if let Ok(_) = env::var("CARGO_FEATURE_REGENERATE_CSS") {
-
-        // Compile stylus stylesheet to css
-        let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
-
-        let theme_dir = Path::new(&manifest_dir).join("src/theme/");
-        let stylus_dir = theme_dir.join("stylus/book.styl");
-
-        if !Command::new("stylus")
-                .arg(format!("{}", stylus_dir.to_str().unwrap()))
-                .arg("--out")
-                .arg(format!("{}", theme_dir.to_str().unwrap()))
-                .arg("--use")
-                .arg("nib")
-                .status().unwrap()
-                .success() {
-            panic!("Stylus encoutered an error");
-        }
-    }
-
-}

ci/install-hub.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Installs the `hub` executable into hub/bin
+set -ex
+case $1 in
+  ubuntu*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-linux-amd64-2.12.8.tgz -o hub.tgz
+    mkdir hub
+    tar -xzvf hub.tgz --strip=1 -C hub
+    ;;
+  macos*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-darwin-amd64-2.12.8.tgz -o hub.tgz
+    mkdir hub
+    tar -xzvf hub.tgz --strip=1 -C hub
+    ;;
+  windows*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-windows-amd64-2.12.8.zip -o hub.zip
+    7z x hub.zip -ohub
+    ;;
+  *)
+    echo "OS should be first parameter, was: $1"
+    ;;
+esac
+
+echo "$PWD/hub/bin" >> $GITHUB_PATH

ci/install-rust.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Install/update rust.
+# The first argument should be the toolchain to install.
+
+set -ex
+if [ -z "$1" ]
+then
+    echo "First parameter must be toolchain to install."
+    exit 1
+fi
+TOOLCHAIN="$1"
+
+rustup set profile minimal
+rustup component remove --toolchain=$TOOLCHAIN rust-docs || echo "already removed"
+rustup update --no-self-update $TOOLCHAIN
+if [ -n "$2" ]
+then
+    TARGET="$2"
+    HOST=$(rustc -Vv | grep ^host: | sed -e "s/host: //g")
+    if [ "$HOST" != "$TARGET" ]
+    then
+        rustup component add llvm-tools-preview --toolchain=$TOOLCHAIN
+        rustup component add rust-std-$TARGET --toolchain=$TOOLCHAIN
+    fi
+fi
+
+rustup default $TOOLCHAIN
+rustup -V
+rustc -Vv
+cargo -V

ci/make-release.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# Builds the release and creates an archive and optionally deploys to GitHub.
+set -ex
+
+if [[ -z "$GITHUB_REF" ]]
+then
+  echo "GITHUB_REF must be set"
+  exit 1
+fi
+# Strip mdbook-refs/tags/ from the start of the ref.
+TAG=${GITHUB_REF#*/tags/}
+
+host=$(rustc -Vv | grep ^host: | sed -e "s/host: //g")
+target=$2
+if [ "$host" != "$target" ]
+then
+  export "CARGO_TARGET_$(echo $target | tr a-z- A-Z_)_LINKER"=rust-lld
+fi
+export CARGO_PROFILE_RELEASE_LTO=true
+cargo build --bin mdbook --release --target $target
+cd target/$target/release
+case $1 in
+  ubuntu*)
+    asset="mdbook-$TAG-$target.tar.gz"
+    tar czf ../../$asset mdbook
+    ;;
+  macos*)
+    asset="mdbook-$TAG-$target.tar.gz"
+    # There is a bug with BSD tar on macOS where the first 8MB of the file are
+    # sometimes all NUL bytes. See https://github.com/actions/cache/issues/403
+    # and https://github.com/rust-lang/cargo/issues/8603 for some more
+    # information. An alternative solution here is to install GNU tar, but
+    # flushing the disk cache seems to work, too.
+    sudo /usr/sbin/purge
+    tar czf ../../$asset mdbook
+    ;;
+  windows*)
+    asset="mdbook-$TAG-$target.zip"
+    7z a ../../$asset mdbook.exe
+    ;;
+  *)
+    echo "OS should be first parameter, was: $1"
+    ;;
+esac
+cd ../..
+
+if [[ -z "$GITHUB_TOKEN" ]]
+then
+  echo "$GITHUB_TOKEN not set, skipping deploy."
+else
+  hub release edit -m "" --attach $asset $TAG
+fi

deploy.sh

@@ -1,42 +0,0 @@
-#!/bin/bash
-
-# Exit on error or variable unset
-set -o errexit -o nounset
-
-NC='\033[39m'
-CYAN='\033[36m'
-GREEN='\033[32m'
-
-rev=$(git rev-parse --short HEAD)
-
-echo -e "${CYAN}Running cargo doc${NC}"
-# Run cargo doc
-cargo doc
-
-echo -e "${CYAN}Running mdbook build${NC}"
-# Run mdbook to generate the book
-target/debug/mdbook build book-example/
-
-echo -e "${CYAN}Copying book to target/doc${NC}"
-# Copy files from rendered book to doc root
-cp -R book-example/book/* target/doc/
-
-cd target/doc
-
-echo -e "${CYAN}Initializing Git${NC}"
-git init
-git config user.name "Mathieu David"
-git config user.email "mathieudavid@mathieudavid.org"
-
-git remote add upstream "https://$GH_TOKEN@github.com/azerupi/mdBook.git"
-git fetch upstream
-git reset upstream/gh-pages
-
-touch .
-
-echo -e "${CYAN}Pushing changes to gh-pages${NC}"
-git add -A .
-git commit -m "rebuild pages at ${rev}"
-git push -q upstream HEAD:gh-pages
-
-echo -e "${GREEN}Deployement done${NC}"

examples/nop-preprocessor.rs

@@ -0,0 +1,160 @@
+use crate::nop_lib::Nop;
+use clap::{Arg, ArgMatches, Command};
+use mdbook::book::Book;
+use mdbook::errors::Error;
+use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext};
+use semver::{Version, VersionReq};
+use std::io;
+use std::process;
+
+pub fn make_app() -> Command {
+    Command::new("nop-preprocessor")
+        .about("A mdbook preprocessor which does precisely nothing")
+        .subcommand(
+            Command::new("supports")
+                .arg(Arg::new("renderer").required(true))
+                .about("Check whether a renderer is supported by this preprocessor"),
+        )
+}
+
+fn main() {
+    let matches = make_app().get_matches();
+
+    // Users will want to construct their own preprocessor here
+    let preprocessor = Nop::new();
+
+    if let Some(sub_args) = matches.subcommand_matches("supports") {
+        handle_supports(&preprocessor, sub_args);
+    } else if let Err(e) = handle_preprocessing(&preprocessor) {
+        eprintln!("{}", e);
+        process::exit(1);
+    }
+}
+
+fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
+    let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?;
+
+    let book_version = Version::parse(&ctx.mdbook_version)?;
+    let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?;
+
+    if !version_req.matches(&book_version) {
+        eprintln!(
+            "Warning: The {} plugin was built against version {} of mdbook, \
+             but we're being called from version {}",
+            pre.name(),
+            mdbook::MDBOOK_VERSION,
+            ctx.mdbook_version
+        );
+    }
+
+    let processed_book = pre.run(&ctx, book)?;
+    serde_json::to_writer(io::stdout(), &processed_book)?;
+
+    Ok(())
+}
+
+fn handle_supports(pre: &dyn Preprocessor, sub_args: &ArgMatches) -> ! {
+    let renderer = sub_args
+        .get_one::<String>("renderer")
+        .expect("Required argument");
+    let supported = pre.supports_renderer(renderer);
+
+    // Signal whether the renderer is supported by exiting with 1 or 0.
+    if supported {
+        process::exit(0);
+    } else {
+        process::exit(1);
+    }
+}
+
+/// The actual implementation of the `Nop` preprocessor. This would usually go
+/// in your main `lib.rs` file.
+mod nop_lib {
+    use super::*;
+
+    /// A no-op preprocessor.
+    pub struct Nop;
+
+    impl Nop {
+        pub fn new() -> Nop {
+            Nop
+        }
+    }
+
+    impl Preprocessor for Nop {
+        fn name(&self) -> &str {
+            "nop-preprocessor"
+        }
+
+        fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book, Error> {
+            // In testing we want to tell the preprocessor to blow up by setting a
+            // particular config value
+            if let Some(nop_cfg) = ctx.config.get_preprocessor(self.name()) {
+                if nop_cfg.contains_key("blow-up") {
+                    anyhow::bail!("Boom!!1!");
+                }
+            }
+
+            // we *are* a no-op preprocessor after all
+            Ok(book)
+        }
+
+        fn supports_renderer(&self, renderer: &str) -> bool {
+            renderer != "not-supported"
+        }
+    }
+
+    #[cfg(test)]
+    mod test {
+        use super::*;
+
+        #[test]
+        fn nop_preprocessor_run() {
+            let input_json = r##"[
+                {
+                    "root": "/path/to/book",
+                    "config": {
+                        "book": {
+                            "authors": ["AUTHOR"],
+                            "language": "en",
+                            "multilingual": false,
+                            "src": "src",
+                            "title": "TITLE"
+                        },
+                        "preprocessor": {
+                            "nop": {}
+                        }
+                    },
+                    "renderer": "html",
+                    "mdbook_version": "0.4.21"
+                },
+                {
+                    "sections": [
+                        {
+                            "Chapter": {
+                                "name": "Chapter 1",
+                                "content": "# Chapter 1\n",
+                                "number": [1],
+                                "sub_items": [],
+                                "path": "chapter_1.md",
+                                "source_path": "chapter_1.md",
+                                "parent_names": []
+                            }
+                        }
+                    ],
+                    "__non_exhaustive": null
+                }
+            ]"##;
+            let input_json = input_json.as_bytes();
+
+            let (ctx, book) = mdbook::preprocess::CmdPreprocessor::parse_input(input_json).unwrap();
+            let expected_book = book.clone();
+            let result = Nop::new().run(&ctx, book);
+            assert!(result.is_ok());
+
+            // The nop-preprocessor should not have made any changes to the book content.
+            let actual_book = result.unwrap();
+            assert_eq!(actual_book, expected_book);
+        }
+    }
+}

guide/book.toml

@@ -0,0 +1,30 @@
+[book]
+title = "mdBook Documentation"
+description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+authors = ["Mathieu David", "Michael-F-Bryan"]
+language = "en"
+
+[rust]
+edition = "2018"
+
+[output.html]
+mathjax-support = true
+site-url = "/mdBook/"
+git-repository-url = "https://github.com/rust-lang/mdBook/tree/master/guide"
+edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"
+
+[output.html.playground]
+editable = true
+line-numbers = true
+
+[output.html.search]
+limit-results = 20
+use-boolean-and = true
+boost-title = 2
+boost-hierarchy = 2
+boost-paragraph = 1
+expand = true
+heading-split-level = 2
+
+[output.html.redirect]
+"/format/config.html" = "configuration/index.html"

guide/src/404.md

@@ -0,0 +1,3 @@
+# Document not found (404)
+
+This URL is invalid, sorry. Try the search instead!

guide/src/README.md

@@ -0,0 +1,41 @@
+# Introduction
+
+**mdBook** is a command line tool to create books with Markdown.
+It is ideal for creating product or API documentation, tutorials, course materials or anything that requires a clean,
+easily navigable and customizable presentation.
+
+* Lightweight [Markdown] syntax helps you focus more on your content
+* Integrated [search] support
+* Color [syntax highlighting] for code blocks for many different languages
+* [Theme] files allow customizing the formatting of the output
+* [Preprocessors] can provide extensions for custom syntax and modifying content
+* [Backends] can render the output to multiple formats
+* Written in [Rust] for speed, safety, and simplicity
+* Automated testing of [Rust code samples]
+
+This guide is an example of what mdBook produces.
+mdBook is used by the Rust programming language project, and [The Rust Programming Language][trpl] book is another fine example of mdBook in action.
+
+[Markdown]: format/markdown.md
+[search]: guide/reading.md#search
+[syntax highlighting]: format/theme/syntax-highlighting.md
+[theme]: format/theme/index.html
+[preprocessors]: format/configuration/preprocessors.md
+[backends]: format/configuration/renderers.md
+[Rust]: https://www.rust-lang.org/
+[trpl]: https://doc.rust-lang.org/book/
+[Rust code samples]: cli/test.md
+
+## Contributing
+
+mdBook is free and open source. You can find the source code on
+[GitHub](https://github.com/rust-lang/mdBook) and issues and feature requests can be posted on
+the [GitHub issue tracker](https://github.com/rust-lang/mdBook/issues). mdBook relies on the community to fix bugs and
+add features: if you'd like to contribute, please read
+the [CONTRIBUTING](https://github.com/rust-lang/mdBook/blob/master/CONTRIBUTING.md) guide and consider opening
+a [pull request](https://github.com/rust-lang/mdBook/pulls).
+
+## License
+
+The mdBook source and documentation are released under
+the [Mozilla Public License v2.0](https://www.mozilla.org/MPL/2.0/).

guide/src/SUMMARY.md

@@ -0,0 +1,43 @@
+# Summary
+
+[Introduction](README.md)
+
+# User Guide
+
+- [Installation](guide/installation.md)
+- [Reading Books](guide/reading.md)
+- [Creating a Book](guide/creating.md)
+
+# Reference Guide
+
+- [Command Line Tool](cli/README.md)
+    - [init](cli/init.md)
+    - [build](cli/build.md)
+    - [watch](cli/watch.md)
+    - [serve](cli/serve.md)
+    - [test](cli/test.md)
+    - [clean](cli/clean.md)
+    - [completions](cli/completions.md)
+- [Format](format/README.md)
+    - [SUMMARY.md](format/summary.md)
+        - [Draft chapter]()
+    - [Configuration](format/configuration/README.md)
+        - [General](format/configuration/general.md)
+        - [Preprocessors](format/configuration/preprocessors.md)
+        - [Renderers](format/configuration/renderers.md)
+        - [Environment Variables](format/configuration/environment-variables.md)
+    - [Theme](format/theme/README.md)
+        - [index.hbs](format/theme/index-hbs.md)
+        - [Syntax highlighting](format/theme/syntax-highlighting.md)
+        - [Editor](format/theme/editor.md)
+    - [MathJax Support](format/mathjax.md)
+    - [mdBook-specific features](format/mdbook.md)
+    - [Markdown](format/markdown.md)
+- [Continuous Integration](continuous-integration.md)
+- [For Developers](for_developers/README.md)
+    - [Preprocessors](for_developers/preprocessors.md)
+    - [Alternative Backends](for_developers/backends.md)
+
+-----------
+
+[Contributors](misc/contributors.md)

guide/src/cli/README.md

@@ -0,0 +1,14 @@
+# Command Line Tool
+
+The `mdbook` command-line tool is used to create and build books.
+After you have [installed](../guide/installation.md) `mdbook`, you can run the `mdbook help` command in your terminal to view the available commands.
+
+This following sections provide in-depth information on the different commands available.
+
+* [`mdbook init <directory>`](init.md) — Creates a new book with minimal boilerplate to start with.
+* [`mdbook build`](build.md) — Renders the book.
+* [`mdbook watch`](watch.md) — Rebuilds the book any time a source file changes.
+* [`mdbook serve`](serve.md) — Runs a web server to view the book, and rebuilds on changes.
+* [`mdbook test`](test.md) — Tests Rust code samples.
+* [`mdbook clean`](clean.md) — Deletes the rendered output.
+* [`mdbook completions`](completions.md) — Support for shell auto-completion.

guide/src/cli/build.md

@@ -0,0 +1,40 @@
+# The build command
+
+The build command is used to render your book:
+
+```bash
+mdbook build
+```
+
+It will try to parse your `SUMMARY.md` file to understand the structure of your
+book and fetch the corresponding files. Note that files mentioned in `SUMMARY.md`
+but not present will be created.
+
+The rendered output will maintain the same directory structure as the source for
+convenience. Large books will therefore remain structured when rendered.
+
+#### Specify a directory
+
+The `build` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
+
+```bash
+mdbook build path/to/book
+```
+
+#### --open
+
+When you use the `--open` (`-o`) flag, mdbook will open the rendered book in
+your default web browser after building it.
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to change the output directory for the
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
+
+-------------------
+
+***Note:*** *The build command copies all files (excluding files with `.md` extension) from the source directory
+into the build directory.*

guide/src/cli/clean.md

@@ -0,0 +1,30 @@
+# The clean command
+
+The clean command is used to delete the generated book and any other build
+artifacts.
+
+```bash
+mdbook clean
+```
+
+#### Specify a directory
+
+The `clean` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
+
+```bash
+mdbook clean path/to/book
+```
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to override the book's output
+directory, which will be deleted by this command. Relative paths are interpreted
+relative to the book's root directory. If not specified it will default to the
+value of the `build.build-dir` key in `book.toml`, or to `./book`.
+
+```bash
+mdbook clean --dest-dir=path/to/book
+```
+
+`path/to/book` could be absolute or relative.

guide/src/cli/completions.md

@@ -0,0 +1,16 @@
+# The completions command
+
+The completions command is used to generate auto-completions for some common shells.
+This means when you type `mdbook` in your shell, you can then press your shell's auto-complete key (usually the Tab key) and it may display what the valid options are, or finish partial input.
+
+The completions first need to be installed for your shell:
+
+```bash
+mdbook completions bash > ~/.local/share/bash-completion/completions/mdbook
+```
+
+The command prints a completion script for the given shell.
+Run `mdbook completions --help` for a list of supported shells.
+
+Where to place the completions depend on which shell you are using and your operating system.
+Consult your shell's documentation for more information one where to place the script.

guide/src/cli/init.md

@@ -0,0 +1,70 @@
+# The init command
+
+There is some minimal boilerplate that is the same for every new book. It's for
+this purpose that mdBook includes an `init` command.
+
+The `init` command is used like this:
+
+```bash
+mdbook init
+```
+
+When using the `init` command for the first time, a couple of files will be set
+up for you:
+```bash
+book-test/
+├── book
+└── src
+    ├── chapter_1.md
+    └── SUMMARY.md
+```
+
+- The `src` directory is where you write your book in markdown. It contains all
+  the source files, configuration files, etc.
+
+- The `book` directory is where your book is rendered. All the output is ready
+  to be uploaded to a server to be seen by your audience.
+
+- The `SUMMARY.md` is the skeleton of your
+  book, and is discussed in more detail [in another
+  chapter](../format/summary.md).
+
+#### Tip: Generate chapters from SUMMARY.md
+
+When a `SUMMARY.md` file already exists, the `init` command will first parse it
+and generate the missing files according to the paths used in the `SUMMARY.md`.
+This allows you to think and create the whole structure of your book and then
+let mdBook generate it for you.
+
+#### Specify a directory
+
+The `init` command can take a directory as an argument to use as the book's root
+instead of the current working directory.
+
+```bash
+mdbook init path/to/book
+```
+
+#### --theme
+
+When you use the `--theme` flag, the default theme will be copied into a
+directory called `theme` in your source directory so that you can modify it.
+
+The theme is selectively overwritten, this means that if you don't want to
+overwrite a specific file, just delete it and the default file will be used.
+
+#### --title
+
+Specify a title for the book. If not supplied, an interactive prompt will ask for 
+a title. 
+
+```bash
+mdbook init --title="my amazing book"
+```
+
+#### --ignore
+
+Create a `.gitignore` file configured to ignore the `book` directory created when [building] a book. 
+If not supplied, an interactive prompt will ask whether it should be created.
+
+[building]: build.md

guide/src/cli/serve.md

@@ -0,0 +1,56 @@
+# The serve command
+
+The serve command is used to preview a book by serving it via HTTP at
+`localhost:3000` by default: 
+
+```bash
+mdbook serve
+```
+
+The `serve` command  watches the book's `src` directory for
+changes, rebuilding the book and refreshing clients for each change; this includes
+re-creating deleted files still mentioned in `SUMMARY.md`! A websocket
+connection is used to trigger the client-side refresh.
+
+***Note:*** *The `serve` command is for testing a book's HTML output, and is not
+intended to be a complete HTTP server for a website.*
+
+#### Specify a directory
+
+The `serve` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
+
+```bash
+mdbook serve path/to/book
+```
+
+### Server options
+
+The `serve` hostname defaults to `localhost`, and the port defaults to `3000`. Either option can be specified on the command line:
+
+```bash
+mdbook serve path/to/book -p 8000 -n 127.0.0.1 
+```
+
+#### --open
+
+When you use the `--open` (`-o`) flag, mdbook will open the book in your
+default web browser after starting the server.
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to change the output directory for the
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
+
+#### Specify exclude patterns
+
+The `serve` command will not automatically trigger a build for files listed in
+the `.gitignore` file in the book root directory. The `.gitignore` file may
+contain file patterns described in the [gitignore
+documentation](https://git-scm.com/docs/gitignore). This can be useful for
+ignoring temporary files created by some editors.
+
+***Note:*** *Only the `.gitignore` from the book root directory is used. Global
+`$HOME/.gitignore` or `.gitignore` files in parent directories are not used.*

guide/src/cli/test.md

@@ -0,0 +1,68 @@
+# The test command
+
+When writing a book, you sometimes need to automate some tests. For example,
+[The Rust Programming Book](https://doc.rust-lang.org/stable/book/) uses a lot
+of code examples that could get outdated. Therefore it is very important for
+them to be able to automatically test these code examples.
+
+mdBook supports a `test` command that will run all available tests in a book. At
+the moment, only rustdoc tests are supported, but this may be expanded upon in
+the future.
+
+#### Disable tests on a code block
+
+rustdoc doesn't test code blocks which contain the `ignore` attribute:
+
+    ```rust,ignore
+    fn main() {}
+    ```
+
+rustdoc also doesn't test code blocks which specify a language other than Rust:
+
+    ```markdown
+    **Foo**: _bar_
+    ```
+
+rustdoc *does* test code blocks which have no language specified:
+
+    ```
+    This is going to cause an error!
+    ```
+
+#### Specify a directory
+
+The `test` command can take a directory as an argument to use as the book's root
+instead of the current working directory.
+
+```bash
+mdbook test path/to/book
+```
+
+#### --library-path
+
+The `--library-path` (`-L`) option allows you to add directories to the library
+search path used by `rustdoc` when it builds and tests the examples. Multiple
+directories can be specified with multiple options (`-L foo -L bar`) or with a
+comma-delimited list (`-L foo,bar`). The path should point to the Cargo
+[build cache](https://doc.rust-lang.org/cargo/guide/build-cache.html) `deps` directory that
+contains the build output of your project. For example, if your Rust project's book is in a directory
+named `my-book`, the following command would include the crate's dependencies when running `test`:
+
+```shell
+mdbook test my-book -L target/debug/deps/
+```
+
+See the `rustdoc` command-line [documentation](https://doc.rust-lang.org/rustdoc/command-line-arguments.html#-l--library-path-where-to-look-for-dependencies)
+for more information.
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to change the output directory for the
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
+
+#### --chapter
+
+The `--chapter` (`-c`) option allows you to test a specific chapter of the
+book using the chapter name or the relative path to the chapter.

guide/src/cli/watch.md

@@ -0,0 +1,40 @@
+# The watch command
+
+The `watch` command is useful when you want your book to be rendered on every
+file change. You could repeatedly issue `mdbook build` every time a file is
+changed. But using `mdbook watch` once will watch your files and will trigger a
+build automatically whenever you modify a file; this includes re-creating
+deleted files still mentioned in `SUMMARY.md`!
+
+#### Specify a directory
+
+The `watch` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
+
+```bash
+mdbook watch path/to/book
+```
+
+#### --open
+
+When you use the `--open` (`-o`) option, mdbook will open the rendered book in
+your default web browser.
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to change the output directory for the
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
+
+
+#### Specify exclude patterns
+
+The `watch` command will not automatically trigger a build for files listed in
+the `.gitignore` file in the book root directory. The `.gitignore` file may
+contain file patterns described in the [gitignore
+documentation](https://git-scm.com/docs/gitignore). This can be useful for
+ignoring temporary files created by some editors.
+
+_Note: Only `.gitignore` from book root directory is used. Global
+`$HOME/.gitignore` or `.gitignore` files in parent directories are not used._

guide/src/continuous-integration.md

@@ -0,0 +1,121 @@
+# Running `mdbook` in Continuous Integration
+
+There are a variety of services such as [GitHub Actions] or [GitLab CI/CD] which can be used to test and deploy your book automatically.
+
+The following provides some general guidelines on how to configure your service to run mdBook.
+Specific recipes can be found at the [Automated Deployment] wiki page.
+
+[GitHub Actions]: https://docs.github.com/en/actions
+[GitLab CI/CD]: https://docs.gitlab.com/ee/ci/
+[Automated Deployment]: https://github.com/rust-lang/mdBook/wiki/Automated-Deployment
+
+## Installing mdBook
+
+There are several different strategies for installing mdBook.
+The particular method depends on your needs and preferences.
+
+### Pre-compiled binaries
+
+Perhaps the easiest method is to use the pre-compiled binaries found on the [GitHub Releases page][releases].
+A simple approach would be to use the popular `curl` CLI tool to download the executable:
+
+```sh
+mkdir bin
+curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.26/mdbook-v0.4.26-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=bin
+bin/mdbook build
+```
+
+Some considerations for this approach:
+
+* This is relatively fast, and does not necessarily require dealing with caching.
+* This does not require installing Rust.
+* Specifying a specific URL means you have to manually update your script to get a new version.
+  This may be a benefit if you want to lock to a specific version.
+  However, some users prefer to automatically get a newer version when they are published.
+* You are reliant on the GitHub CDN being available.
+
+[releases]: https://github.com/rust-lang/mdBook/releases
+
+### Building from source
+
+Building from source will require having Rust installed.
+Some services have Rust pre-installed, but if your service does not, you will need to add a step to install it.
+
+After Rust is installed, `cargo install` can be used to build and install mdBook.
+We recommend using a SemVer version specifier so that you get the latest **non-breaking** version of mdBook.
+For example:
+
+```sh
+cargo install mdbook --no-default-features --features search --vers "^0.4" --locked
+```
+
+This includes several recommended options:
+
+* `--no-default-features` — Disables features like the HTTP server used by `mdbook serve` that is likely not needed on CI.
+  This will speed up the build time significantly.
+* `--features search` — Disabling default features means you should then manually enable features that you want, such as the built-in [search] capability.
+* `--vers "^0.4"` — This will install the most recent version of the `0.4` series.
+  However, versions after like `0.5.0` won't be installed, as they may break your build.
+  Cargo will automatically upgrade mdBook if you have an older version already installed.
+* `--locked` — This will use the dependencies that were used when mdBook was released.
+  Without `--locked`, it will use the latest version of all dependencies, which may include some fixes since the last release, but may also (rarely) cause build problems.
+
+You will likely want to investigate caching options, as building mdBook can be somewhat slow.
+
+[search]: guide/reading.md#search
+
+## Running tests
+
+You may want to run tests using [`mdbook test`] every time you push a change or create a pull request.
+This can be used to validate Rust code examples in the book.
+
+This will require having Rust installed.
+Some services have Rust pre-installed, but if your service does not, you will need to add a step to install it.
+
+Other than making sure the appropriate version of Rust is installed, there's not much more than just running `mdbook test` from the book directory.
+
+You may also want to consider running other kinds of tests, like [mdbook-linkcheck] which will check for broken links.
+Or if you have your own style checks, spell checker, or any other tests it might be good to run them in CI.
+
+[`mdbook test`]: cli/test.md
+[mdbook-linkcheck]: https://github.com/Michael-F-Bryan/mdbook-linkcheck#continuous-integration
+
+## Deploying
+
+You may want to automatically deploy your book.
+Some may want to do this with every time a change is pushed, and others may want to only deploy when a specific release is tagged.
+
+You'll also need to understand the specifics on how to push a change to your web service.
+For example, [GitHub Pages] just requires committing the output onto a specific git branch.
+Other services may require using something like SSH to connect to a remote server.
+
+The basic outline is that you need to run `mdbook build` to generate the output, and then transfer the files (which are in the `book` directory) to the correct location.
+
+You may then want to consider if you need to invalidate any caches on your web service.
+
+See the [Automated Deployment] wiki page for examples of various different services.
+
+[GitHub Pages]: https://docs.github.com/en/pages
+
+### 404 handling
+
+mdBook automatically generates a 404 page to be used for broken links.
+The default output is a file named `404.html` at the root of the book.
+Some services like [GitHub Pages] will automatically use this page for broken links.
+For other services, you may want to consider configuring the web server to use this page as it will provide the reader navigation to get back to the book.
+
+If your book is not deployed at the root of the domain, then you should set the [`output.html.site-url`] setting so that the 404 page works correctly.
+It needs to know where the book is deployed in order to load the static files (like CSS) correctly.
+For example, this guide is deployed at <https://rust-lang.github.io/mdBook/>, and the `site-url` setting is configured like this:
+
+```toml
+# book.toml
+[output.html]
+site-url = "/mdBook/"
+```
+
+You can customize the look of the 404 page by creating a file named `src/404.md` in your book.
+If you want to use a different filename, you can set [`output.html.input-404`] to a different filename.
+
+[`output.html.site-url`]: format/configuration/renderers.md#html-renderer-options
+[`output.html.input-404`]: format/configuration/renderers.md#html-renderer-options

guide/src/for_developers/README.md

@@ -0,0 +1,47 @@
+# For Developers
+
+While `mdbook` is mainly used as a command line tool, you can also import the
+underlying library directly and use that to manage a book. It also has a fairly
+flexible plugin mechanism, allowing you to create your own custom tooling and
+consumers (often referred to as *backends*) if you need to do some analysis of
+the book or render it in a different format.
+
+The *For Developers* chapters are here to show you the more advanced usage of
+`mdbook`.
+
+The two main ways a developer can hook into the book's build process is via,
+
+- [Preprocessors](preprocessors.md)
+- [Alternative Backends](backends.md)
+
+
+## The Build Process
+
+The process of rendering a book project goes through several steps.
+
+1. Load the book
+    - Parse the `book.toml`, falling back to the default `Config` if it doesn't
+       exist
+    - Load the book chapters into memory
+    - Discover which preprocessors/backends should be used
+2. For each backend:
+   1. Run all the preprocessors.
+   2. Call the backend to render the processed result.
+
+
+## Using `mdbook` as a Library
+
+The `mdbook` binary is just a wrapper around the `mdbook` crate, exposing its
+functionality as a command-line program. As such it is quite easy to create your
+own programs which use `mdbook` internally, adding your own functionality (e.g.
+a custom preprocessor) or tweaking the build process.
+
+The easiest way to find out how to use the `mdbook` crate is by looking at the
+[API Docs]. The top level documentation explains how one would use the
+[`MDBook`] type to load and build a book, while the [config] module gives a good
+explanation on the configuration system.
+
+
+[`MDBook`]: https://docs.rs/mdbook/*/mdbook/book/struct.MDBook.html
+[API Docs]: https://docs.rs/mdbook/*/mdbook/
+[config]: https://docs.rs/mdbook/*/mdbook/config/index.html

guide/src/for_developers/backends.md

@@ -0,0 +1,346 @@
+# Alternative Backends
+
+A "backend" is simply a program which `mdbook` will invoke during the book
+rendering process. This program is passed a JSON representation of the book and
+configuration information via `stdin`. Once the backend receives this
+information it is free to do whatever it wants.
+
+See [Configuring Renderers](../format/configuration/renderers.md) for more information about using backends.
+
+The community has developed several backends.
+See the [Third Party Plugins] wiki page for a list of available backends.
+
+## Setting Up
+
+This page will step you through creating your own alternative backend in the form
+of a simple word counting program. Although it will be written in Rust, there's
+no reason why it couldn't be accomplished using something like Python or Ruby.
+
+First you'll want to create a new binary program and add `mdbook` as a
+dependency.
+
+```shell
+$ cargo new --bin mdbook-wordcount
+$ cd mdbook-wordcount
+$ cargo add mdbook
+```
+
+When our `mdbook-wordcount` plugin is invoked, `mdbook` will send it a JSON
+version of [`RenderContext`] via our plugin's `stdin`. For convenience, there's
+a [`RenderContext::from_json()`] constructor which will load a `RenderContext`.
+
+This is all the boilerplate necessary for our backend to load the book.
+
+```rust
+// src/main.rs
+extern crate mdbook;
+
+use std::io;
+use mdbook::renderer::RenderContext;
+
+fn main() {
+    let mut stdin = io::stdin();
+    let ctx = RenderContext::from_json(&mut stdin).unwrap();
+}
+```
+
+> **Note:** The `RenderContext` contains a `version` field. This lets backends
+  figure out whether they are compatible with the version of `mdbook` it's being
+  called by. This `version` comes directly from the corresponding field in
+  `mdbook`'s `Cargo.toml`.
+
+  It is recommended that backends use the [`semver`] crate to inspect this field
+  and emit a warning if there may be a compatibility issue.
+
+
+## Inspecting the Book
+
+Now our backend has a copy of the book, lets count how many words are in each
+chapter!
+
+Because the `RenderContext` contains a [`Book`] field (`book`), and a `Book` has
+the [`Book::iter()`] method for iterating over all items in a `Book`, this step
+turns out to be just as easy as the first.
+
+```rust
+
+fn main() {
+    let mut stdin = io::stdin();
+    let ctx = RenderContext::from_json(&mut stdin).unwrap();
+
+    for item in ctx.book.iter() {
+        if let BookItem::Chapter(ref ch) = *item {
+            let num_words = count_words(ch);
+            println!("{}: {}", ch.name, num_words);
+        }
+    }
+}
+
+fn count_words(ch: &Chapter) -> usize {
+    ch.content.split_whitespace().count()
+}
+```
+
+
+## Enabling the Backend
+
+Now we've got the basics running, we want to actually use it. First, install the
+program.
+
+```shell
+$ cargo install --path .
+```
+
+Then `cd` to the particular book you'd like to count the words of and update its
+`book.toml` file.
+
+```diff
+  [book]
+  title = "mdBook Documentation"
+  description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+  authors = ["Mathieu David", "Michael-F-Bryan"]
+
++ [output.html]
+
++ [output.wordcount]
+```
+
+When it loads a book into memory, `mdbook` will inspect your `book.toml` file to
+try and figure out which backends to use by looking for all `output.*` tables.
+If none are provided it'll fall back to using the default HTML renderer.
+
+Notably, this means if you want to add your own custom backend you'll also need
+to make sure to add the HTML backend, even if its table just stays empty.
+
+Now you just need to build your book like normal, and everything should *Just
+Work*.
+
+```shell
+$ mdbook build
+...
+2018-01-16 07:31:15 [INFO] (mdbook::renderer): Invoking the "mdbook-wordcount" renderer
+mdBook: 126
+Command Line Tool: 224
+init: 283
+build: 145
+watch: 146
+serve: 292
+test: 139
+Format: 30
+SUMMARY.md: 259
+Configuration: 784
+Theme: 304
+index.hbs: 447
+Syntax highlighting: 314
+MathJax Support: 153
+Rust code specific features: 148
+For Developers: 788
+Alternative Backends: 710
+Contributors: 85
+```
+
+The reason we didn't need to specify the full name/path of our `wordcount`
+backend is because `mdbook` will try to *infer* the program's name via
+convention. The executable for the `foo` backend is typically called
+`mdbook-foo`, with an associated `[output.foo]` entry in the `book.toml`. To
+explicitly tell `mdbook` what command to invoke (it may require command-line
+arguments or be an interpreted script), you can use the `command` field.
+
+```diff
+  [book]
+  title = "mdBook Documentation"
+  description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+  authors = ["Mathieu David", "Michael-F-Bryan"]
+
+  [output.html]
+
+  [output.wordcount]
++ command = "python /path/to/wordcount.py"
+```
+
+
+## Configuration
+
+Now imagine you don't want to count the number of words on a particular chapter
+(it might be generated text/code, etc). The canonical way to do this is via the
+usual `book.toml` configuration file by adding items to your `[output.foo]`
+table.
+
+The `Config` can be treated roughly as a nested hashmap which lets you call
+methods like `get()` to access the config's contents, with a
+`get_deserialized()` convenience method for retrieving a value and automatically
+deserializing to some arbitrary type `T`.
+
+To implement this, we'll create our own serializable `WordcountConfig` struct
+which will encapsulate all configuration for this backend.
+
+First add `serde` and `serde_derive` to your `Cargo.toml`,
+
+```
+$ cargo add serde serde_derive
+```
+
+And then you can create the config struct,
+
+```rust
+extern crate serde;
+#[macro_use]
+extern crate serde_derive;
+
+...
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+#[serde(default, rename_all = "kebab-case")]
+pub struct WordcountConfig {
+  pub ignores: Vec<String>,
+}
+```
+
+Now we just need to deserialize the `WordcountConfig` from our `RenderContext`
+and then add a check to make sure we skip ignored chapters.
+
+```diff
+  fn main() {
+      let mut stdin = io::stdin();
+      let ctx = RenderContext::from_json(&mut stdin).unwrap();
++     let cfg: WordcountConfig = ctx.config
++         .get_deserialized("output.wordcount")
++         .unwrap_or_default();
+
+      for item in ctx.book.iter() {
+          if let BookItem::Chapter(ref ch) = *item {
++             if cfg.ignores.contains(&ch.name) {
++                 continue;
++             }
++
+              let num_words = count_words(ch);
+              println!("{}: {}", ch.name, num_words);
+          }
+      }
+  }
+```
+
+
+## Output and Signalling Failure
+
+While it's nice to print word counts to the terminal when a book is built, it
+might also be a good idea to output them to a file somewhere. `mdbook` tells a
+backend where it should place any generated output via the `destination` field
+in [`RenderContext`].
+
+```diff
++ use std::fs::{self, File};
++ use std::io::{self, Write};
+- use std::io;
+  use mdbook::renderer::RenderContext;
+  use mdbook::book::{BookItem, Chapter};
+
+  fn main() {
+    ...
+
++     let _ = fs::create_dir_all(&ctx.destination);
++     let mut f = File::create(ctx.destination.join("wordcounts.txt")).unwrap();
++
+      for item in ctx.book.iter() {
+          if let BookItem::Chapter(ref ch) = *item {
+              ...
+
+              let num_words = count_words(ch);
+              println!("{}: {}", ch.name, num_words);
++             writeln!(f, "{}: {}", ch.name, num_words).unwrap();
+          }
+      }
+  }
+```
+
+> **Note:** There is no guarantee that the destination directory exists or is
+> empty (`mdbook` may leave the previous contents to let backends do caching),
+> so it's always a good idea to create it with `fs::create_dir_all()`.
+>
+> If the destination directory already exists, don't assume it will be empty.
+> To allow backends to cache the results from previous runs, `mdbook` may leave
+> old content in the directory.
+
+There's always the possibility that an error will occur while processing a book
+(just look at all the `unwrap()`'s we've written already), so `mdbook` will
+interpret a non-zero exit code as a rendering failure.
+
+For example, if we wanted to make sure all chapters have an *even* number of
+words, erroring out if an odd number is encountered, then you may do something
+like this:
+
+```diff
++ use std::process;
+  ...
+
+  fn main() {
+      ...
+
+      for item in ctx.book.iter() {
+          if let BookItem::Chapter(ref ch) = *item {
+              ...
+
+              let num_words = count_words(ch);
+              println!("{}: {}", ch.name, num_words);
+              writeln!(f, "{}: {}", ch.name, num_words).unwrap();
+
++             if cfg.deny_odds && num_words % 2 == 1 {
++               eprintln!("{} has an odd number of words!", ch.name);
++               process::exit(1);
+              }
+          }
+      }
+  }
+
+  #[derive(Debug, Default, Serialize, Deserialize)]
+  #[serde(default, rename_all = "kebab-case")]
+  pub struct WordcountConfig {
+      pub ignores: Vec<String>,
++     pub deny_odds: bool,
+  }
+```
+
+Now, if we reinstall the backend and build a book,
+
+```shell
+$ cargo install --path . --force
+$ mdbook build /path/to/book
+...
+2018-01-16 21:21:39 [INFO] (mdbook::renderer): Invoking the "wordcount" renderer
+mdBook: 126
+Command Line Tool: 224
+init: 283
+init has an odd number of words!
+2018-01-16 21:21:39 [ERROR] (mdbook::renderer): Renderer exited with non-zero return code.
+2018-01-16 21:21:39 [ERROR] (mdbook::utils): Error: Rendering failed
+2018-01-16 21:21:39 [ERROR] (mdbook::utils):    Caused By: The "mdbook-wordcount" renderer failed
+```
+
+As you've probably already noticed, output from the plugin's subprocess is
+immediately passed through to the user. It is encouraged for plugins to follow
+the "rule of silence" and only generate output when necessary (e.g. an error in
+generation or a warning).
+
+All environment variables are passed through to the backend, allowing you to use
+the usual `RUST_LOG` to control logging verbosity.
+
+## Wrapping Up
+
+Although contrived, hopefully this example was enough to show how you'd create
+an alternative backend for `mdbook`. If you feel it's missing something, don't
+hesitate to create an issue in the [issue tracker] so we can improve the user
+guide.
+
+The existing backends mentioned towards the start of this chapter should serve
+as a good example of how it's done in real life, so feel free to skim through
+the source code or ask questions.
+
+
+[Third Party Plugins]: https://github.com/rust-lang/mdBook/wiki/Third-party-plugins
+[`RenderContext`]: https://docs.rs/mdbook/*/mdbook/renderer/struct.RenderContext.html
+[`RenderContext::from_json()`]: https://docs.rs/mdbook/*/mdbook/renderer/struct.RenderContext.html#method.from_json
+[`semver`]: https://crates.io/crates/semver
+[`Book`]: https://docs.rs/mdbook/*/mdbook/book/struct.Book.html
+[`Book::iter()`]: https://docs.rs/mdbook/*/mdbook/book/struct.Book.html#method.iter
+[`Config`]: https://docs.rs/mdbook/*/mdbook/config/struct.Config.html
+[issue tracker]: https://github.com/rust-lang/mdBook/issues

guide/src/for_developers/mdbook-wordcount/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "mdbook-wordcount"
+version = "0.1.0"
+authors = ["Michael Bryan <michaelfbryan@gmail.com>"]
+
+[dependencies]
+mdbook = { path = "../../../..", version = "*" }
+serde = "1.0"
+serde_derive = "1.0"

guide/src/for_developers/mdbook-wordcount/src/main.rs

@@ -0,0 +1,49 @@
+extern crate mdbook;
+extern crate serde;
+#[macro_use]
+extern crate serde_derive;
+
+use std::process;
+use std::fs::{self, File};
+use std::io::{self, Write};
+use mdbook::renderer::RenderContext;
+use mdbook::book::{BookItem, Chapter};
+
+fn main() {
+    let mut stdin = io::stdin();
+    let ctx = RenderContext::from_json(&mut stdin).unwrap();
+    let cfg: WordcountConfig = ctx.config
+        .get_deserialized("output.wordcount")
+        .unwrap_or_default();
+
+    let _ = fs::create_dir_all(&ctx.destination);
+    let mut f = File::create(ctx.destination.join("wordcounts.txt")).unwrap();
+
+    for item in ctx.book.iter() {
+        if let BookItem::Chapter(ref ch) = *item {
+            if cfg.ignores.contains(&ch.name) {
+                continue;
+            }
+
+            let num_words = count_words(ch);
+            println!("{}: {}", ch.name, num_words);
+            writeln!(f, "{}: {}", ch.name, num_words).unwrap();
+
+            if cfg.deny_odds && num_words % 2 == 1 {
+                eprintln!("{} has an odd number of words!", ch.name);
+                process::exit(1);
+            }
+        }
+    }
+}
+
+fn count_words(ch: &Chapter) -> usize {
+    ch.content.split_whitespace().count()
+}
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+#[serde(default, rename_all = "kebab-case")]
+pub struct WordcountConfig {
+    pub ignores: Vec<String>,
+    pub deny_odds: bool,
+}

guide/src/for_developers/preprocessors.md

@@ -0,0 +1,134 @@
+# Preprocessors
+
+A *preprocessor* is simply a bit of code which gets run immediately after the
+book is loaded and before it gets rendered, allowing you to update and mutate
+the book. Possible use cases are:
+
+- Creating custom helpers like `\{{#include /path/to/file.md}}`
+- Substituting in latex-style expressions (`$$ \frac{1}{3} $$`) with their
+  mathjax equivalents
+
+See [Configuring Preprocessors](../format/configuration/preprocessors.md) for more information about using preprocessors.
+
+## Hooking Into MDBook
+
+MDBook uses a fairly simple mechanism for discovering third party plugins.
+A new table is added to `book.toml` (e.g. `[preprocessor.foo]` for the `foo`
+preprocessor) and then `mdbook` will try to invoke the `mdbook-foo` program as
+part of the build process.
+
+Once the preprocessor has been defined and the build process starts, mdBook executes the command defined in the `preprocessor.foo.command` key twice.
+The first time it runs the preprocessor to determine if it supports the given renderer.
+mdBook passes two arguments to the process: the first argument is the string `supports` and the second argument is the renderer name.
+The preprocessor should exit with a status code 0 if it supports the given renderer, or return a non-zero exit code if it does not.
+
+If the preprocessor supports the renderer, then mdbook runs it a second time, passing JSON data into stdin.
+The JSON consists of an array of `[context, book]` where `context` is the serialized object [`PreprocessorContext`] and `book` is a [`Book`] object containing the content of the book.
+
+The preprocessor should return the JSON format of the [`Book`] object to stdout, with any modifications it wishes to perform.
+
+The easiest way to get started is by creating your own implementation of the
+`Preprocessor` trait (e.g. in `lib.rs`) and then creating a shell binary which
+translates inputs to the correct `Preprocessor` method. For convenience, there
+is [an example no-op preprocessor] in the `examples/` directory which can easily
+be adapted for other preprocessors.
+
+<details>
+<summary>Example no-op preprocessor</summary>
+
+```rust
+// nop-preprocessors.rs
+
+{{#include ../../../examples/nop-preprocessor.rs}}
+```
+</details>
+
+## Hints For Implementing A Preprocessor
+
+By pulling in `mdbook` as a library, preprocessors can have access to the
+existing infrastructure for dealing with books.
+
+For example, a custom preprocessor could use the
+[`CmdPreprocessor::parse_input()`] function to deserialize the JSON written to
+`stdin`. Then each chapter of the `Book` can be mutated in-place via
+[`Book::for_each_mut()`], and then written to `stdout` with the `serde_json`
+crate.
+
+Chapters can be accessed either directly (by recursively iterating over
+chapters) or via the `Book::for_each_mut()` convenience method.
+
+The `chapter.content` is just a string which happens to be markdown. While it's
+entirely possible to use regular expressions or do a manual find & replace,
+you'll probably want to process the input into something more computer-friendly.
+The [`pulldown-cmark`][pc] crate implements a production-quality event-based
+Markdown parser, with the [`pulldown-cmark-to-cmark`][pctc] crate allowing you to
+translate events back into markdown text.
+
+The following code block shows how to remove all emphasis from markdown,
+without accidentally breaking the document.
+
+```rust
+fn remove_emphasis(
+    num_removed_items: &mut usize,
+    chapter: &mut Chapter,
+) -> Result<String> {
+    let mut buf = String::with_capacity(chapter.content.len());
+
+    let events = Parser::new(&chapter.content).filter(|e| {
+        let should_keep = match *e {
+            Event::Start(Tag::Emphasis)
+            | Event::Start(Tag::Strong)
+            | Event::End(Tag::Emphasis)
+            | Event::End(Tag::Strong) => false,
+            _ => true,
+        };
+        if !should_keep {
+            *num_removed_items += 1;
+        }
+        should_keep
+    });
+
+    cmark(events, &mut buf, None).map(|_| buf).map_err(|err| {
+        Error::from(format!("Markdown serialization failed: {}", err))
+    })
+}
+```
+
+For everything else, have a look [at the complete example][example].
+
+## Implementing a preprocessor with a different language
+
+The fact that mdBook utilizes stdin and stdout to communicate with the preprocessors makes it easy to implement them in a language other than Rust.
+The following code shows how to implement a simple preprocessor in Python, which will modify the content of the first chapter.
+The example below follows the configuration shown above with `preprocessor.foo.command` actually pointing to a Python script.
+
+```python
+import json
+import sys
+
+
+if __name__ == '__main__':
+    if len(sys.argv) > 1: # we check if we received any argument
+        if sys.argv[1] == "supports": 
+            # then we are good to return an exit status code of 0, since the other argument will just be the renderer's name
+            sys.exit(0)
+
+    # load both the context and the book representations from stdin
+    context, book = json.load(sys.stdin)
+    # and now, we can just modify the content of the first chapter
+    book['sections'][0]['Chapter']['content'] = '# Hello'
+    # we are done with the book's modification, we can just print it to stdout, 
+    print(json.dumps(book))
+```
+
+
+
+[preprocessor-docs]: https://docs.rs/mdbook/latest/mdbook/preprocess/trait.Preprocessor.html
+[pc]: https://crates.io/crates/pulldown-cmark
+[pctc]: https://crates.io/crates/pulldown-cmark-to-cmark
+[example]: https://github.com/rust-lang/mdBook/blob/master/examples/nop-preprocessor.rs
+[an example no-op preprocessor]: https://github.com/rust-lang/mdBook/blob/master/examples/nop-preprocessor.rs
+[`CmdPreprocessor::parse_input()`]: https://docs.rs/mdbook/latest/mdbook/preprocess/trait.Preprocessor.html#method.parse_input
+[`Book::for_each_mut()`]: https://docs.rs/mdbook/latest/mdbook/book/struct.Book.html#method.for_each_mut
+[`PreprocessorContext`]: https://docs.rs/mdbook/latest/mdbook/preprocess/struct.PreprocessorContext.html
+[`Book`]: https://docs.rs/mdbook/latest/mdbook/book/struct.Book.html

guide/src/format/README.md

@@ -4,5 +4,5 @@ In this section you will learn how to:
 
 - Structure your book correctly
 - Format your `SUMMARY.md` file
-- Configure your book using `book.json`
+- Configure your book using `book.toml`
 - Customize your theme

guide/src/format/configuration/README.md

@@ -0,0 +1,12 @@
+# Configuration
+
+This section details the configuration options available in the ***book.toml***:
+- **[General]** configuration including the `book`, `rust`, `build` sections
+- **[Preprocessor]** configuration for default and custom book preprocessors
+- **[Renderer]** configuration for the HTML, Markdown and custom renderers
+- **[Environment Variable]** configuration for overriding configuration options in your environment
+
+[General]: general.md
+[Preprocessor]: preprocessors.md
+[Renderer]: renderers.md
+[Environment Variable]: environment-variables.md

guide/src/format/configuration/environment-variables.md

@@ -0,0 +1,38 @@
+# Environment Variables
+
+All configuration values can be overridden from the command line by setting the
+corresponding environment variable. Because many operating systems restrict
+environment variables to be alphanumeric characters or `_`, the configuration
+key needs to be formatted slightly differently to the normal `foo.bar.baz` form.
+
+Variables starting with `MDBOOK_` are used for configuration. The key is created
+by removing the `MDBOOK_` prefix and turning the resulting string into
+`kebab-case`. Double underscores (`__`) separate nested keys, while a single
+underscore (`_`) is replaced with a dash (`-`).
+
+For example:
+
+- `MDBOOK_foo` -> `foo`
+- `MDBOOK_FOO` -> `foo`
+- `MDBOOK_FOO__BAR` -> `foo.bar`
+- `MDBOOK_FOO_BAR` -> `foo-bar`
+- `MDBOOK_FOO_bar__baz` -> `foo-bar.baz`
+
+So by setting the `MDBOOK_BOOK__TITLE` environment variable you can override the
+book's title without needing to touch your `book.toml`.
+
+> **Note:** To facilitate setting more complex config items, the value of an
+> environment variable is first parsed as JSON, falling back to a string if the
+> parse fails.
+>
+> This means, if you so desired, you could override all book metadata when
+> building the book with something like
+>
+> ```shell
+> $ export MDBOOK_BOOK='{"title": "My Awesome Book", "authors": ["Michael-F-Bryan"]}'
+> $ mdbook build
+> ```
+
+The latter case may be useful in situations where `mdbook` is invoked from a
+script or CI, where it sometimes isn't possible to update the `book.toml` before
+building.

guide/src/format/configuration/general.md

@@ -0,0 +1,114 @@
+# General Configuration
+
+You can configure the parameters for your book in the ***book.toml*** file.
+
+Here is an example of what a ***book.toml*** file might look like:
+
+```toml
+[book]
+title = "Example book"
+authors = ["John Doe"]
+description = "The example book covers examples."
+
+[rust]
+edition = "2018"
+
+[build]
+build-dir = "my-example-book"
+create-missing = false
+
+[preprocessor.index]
+
+[preprocessor.links]
+
+[output.html]
+additional-css = ["custom.css"]
+
+[output.html.search]
+limit-results = 15
+```
+
+## Supported configuration options
+
+It is important to note that **any** relative path specified in the
+configuration will always be taken relative from the root of the book where the
+configuration file is located.
+
+### General metadata
+
+This is general information about your book.
+
+- **title:** The title of the book
+- **authors:** The author(s) of the book
+- **description:** A description for the book, which is added as meta
+  information in the html `<head>` of each page
+- **src:** By default, the source directory is found in the directory named
+  `src` directly under the root folder. But this is configurable with the `src`
+  key in the configuration file.
+- **language:** The main language of the book, which is used as a language attribute `<html lang="en">` for example.
+
+**book.toml**
+```toml
+[book]
+title = "Example book"
+authors = ["John Doe", "Jane Doe"]
+description = "The example book covers examples."
+src = "my-src"  # the source files will be found in `root/my-src` instead of `root/src`
+language = "en"
+```
+
+### Rust options
+
+Options for the Rust language, relevant to running tests and playground
+integration.
+
+```toml
+[rust]
+edition = "2015"   # the default edition for code blocks
+```
+
+- **edition**: Rust edition to use by default for the code snippets. Default
+  is "2015". Individual code blocks can be controlled with the `edition2015`, 
+  `edition2018` or `edition2021` annotations, such as:
+
+  ~~~text
+  ```rust,edition2015
+  // This only works in 2015.
+  let try = true;
+  ```
+  ~~~
+
+### Build options
+
+This controls the build process of your book.
+
+```toml
+[build]
+build-dir = "book"                # the directory where the output is placed
+create-missing = true             # whether or not to create missing pages
+use-default-preprocessors = true  # use the default preprocessors
+extra-watch-dirs = []             # directories to watch for triggering builds
+```
+
+- **build-dir:** The directory to put the rendered book in. By default this is
+  `book/` in the book's root directory.
+  This can overridden with the `--dest-dir` CLI option.
+- **create-missing:** By default, any missing files specified in `SUMMARY.md`
+  will be created when the book is built (i.e. `create-missing = true`). If this
+  is `false` then the build process will instead exit with an error if any files
+  do not exist.
+- **use-default-preprocessors:** Disable the default preprocessors of (`links` &
+  `index`) by setting this option to `false`.
+
+  If you have the same, and/or other preprocessors declared via their table
+  of configuration, they will run instead.
+
+  - For clarity, with no preprocessor configuration, the default `links` and
+    `index` will run.
+  - Setting `use-default-preprocessors = false` will disable these
+    default preprocessors from running.
+  - Adding `[preprocessor.links]`, for example, will ensure, regardless of
+    `use-default-preprocessors` that `links` it will run.
+- **extra-watch-dirs**: A list of paths to directories that will be watched in
+  the `watch` and `serve` commands. Changes to files under these directories will
+  trigger rebuilds. Useful if your book depends on files outside its `src` directory.

guide/src/format/configuration/preprocessors.md

@@ -0,0 +1,87 @@
+# Configuring Preprocessors
+
+Preprocessors are extensions that can modify the raw Markdown source before it gets sent to the renderer.
+
+The following preprocessors are built-in and included by default:
+
+- `links`: Expands the `{{ #playground }}`, `{{ #include }}`, and `{{ #rustdoc_include }}` handlebars
+  helpers in a chapter to include the contents of a file.
+  See [Including files] for more.
+- `index`: Convert all chapter files named `README.md` into `index.md`. That is
+  to say, all `README.md` would be rendered to an index file `index.html` in the
+  rendered book.
+
+The built-in preprocessors can be disabled with the [`build.use-default-preprocessors`] config option.
+
+The community has developed several preprocessors.
+See the [Third Party Plugins] wiki page for a list of available preprocessors.
+
+For information on how to create a new preprocessor, see the [Preprocessors for Developers] chapter.
+
+[Including files]: ../mdbook.md#including-files
+[`build.use-default-preprocessors`]: general.md#build-options
+[Third Party Plugins]: https://github.com/rust-lang/mdBook/wiki/Third-party-plugins
+[Preprocessors for Developers]: ../../for_developers/preprocessors.md
+
+## Custom Preprocessor Configuration
+
+Preprocessors can be added by including a `preprocessor` table in `book.toml` with the name of the preprocessor.
+For example, if you have a preprocessor called `mdbook-example`, then you can include it with:
+
+```toml
+[preprocessor.example]
+```
+
+With this table, mdBook will execute the `mdbook-example` preprocessor.
+
+This table can include additional key-value pairs that are specific to the preprocessor.
+For example, if our example prepocessor needed some extra configuration options:
+
+```toml
+[preprocessor.example]
+some-extra-feature = true
+```
+
+## Locking a Preprocessor dependency to a renderer
+
+You can explicitly specify that a preprocessor should run for a renderer by
+binding the two together.
+
+```toml
+[preprocessor.example]
+renderers = ["html"]  # example preprocessor only runs with the HTML renderer
+```
+
+## Provide Your Own Command
+
+By default when you add a `[preprocessor.foo]` table to your `book.toml` file,
+`mdbook` will try to invoke the `mdbook-foo` executable. If you want to use a
+different program name or pass in command-line arguments, this behaviour can
+be overridden by adding a `command` field.
+
+```toml
+[preprocessor.random]
+command = "python random.py"
+```
+
+## Require A Certain Order
+
+The order in which preprocessors are run can be controlled with the `before` and `after` fields.
+For example, suppose you want your `linenos` preprocessor to process lines that may have been `{{#include}}`d; then you want it to run after the built-in `links` preprocessor, which you can require using either the `before` or `after` field:
+
+```toml
+[preprocessor.linenos]
+after = [ "links" ]
+```
+
+or
+
+```toml
+[preprocessor.links]
+before = [ "linenos" ]
+```
+
+It would also be possible, though redundant, to specify both of the above in the same config file.
+
+Preprocessors having the same priority specified through `before` and `after` are sorted by name.
+Any infinite loops will be detected and produce an error.

guide/src/format/configuration/renderers.md

@@ -0,0 +1,303 @@
+# Configuring Renderers
+
+Renderers (also called "backends") are responsible for creating the output of the book.
+
+The following backends are built-in:
+
+* [`html`](#html-renderer-options) — This renders the book to HTML.
+  This is enabled by default if no other `[output]` tables are defined in `book.toml`.
+* [`markdown`](#markdown-renderer) — This outputs the book as markdown after running the preprocessors.
+  This is useful for debugging preprocessors.
+
+The community has developed several backends.
+See the [Third Party Plugins] wiki page for a list of available backends.
+
+For information on how to create a new backend, see the [Backends for Developers] chapter.
+
+[Third Party Plugins]: https://github.com/rust-lang/mdBook/wiki/Third-party-plugins
+[Backends for Developers]: ../../for_developers/backends.md
+
+## Output tables
+
+Backends can be added by including a `output` table in `book.toml` with the name of the backend.
+For example, if you have a backend called `mdbook-wordcount`, then you can include it with:
+
+```toml
+[output.wordcount]
+```
+
+With this table, mdBook will execute the `mdbook-wordcount` backend.
+
+This table can include additional key-value pairs that are specific to the backend.
+For example, if our example backend needed some extra configuration options:
+
+```toml
+[output.wordcount]
+ignores = ["Example Chapter"]
+```
+
+If you define any `[output]` tables, then the `html` backend is not enabled by default.
+If you want to keep the `html` backend running, then just include it in the `book.toml` file.
+For example:
+
+```toml
+[book]
+title = "My Awesome Book"
+
+[output.wordcount]
+
+[output.html]
+```
+
+If more than one `output` table is included, this changes the behavior for the layout of the output directory.
+If there is only one backend, then it places its output directly in the `book` directory (see [`build.build-dir`] to override this location).
+If there is more than one backend, then each backend is placed in a separate directory underneath `book`.
+For example, the above would have directories `book/html` and `book/wordcount`.
+
+[`build.build-dir`]: general.md#build-options
+
+### Custom backend commands
+
+By default when you add an `[output.foo]` table to your `book.toml` file,
+`mdbook` will try to invoke the `mdbook-foo` executable.
+If you want to use a different program name or pass in command-line arguments,
+this behaviour can be overridden by adding a `command` field.
+
+```toml
+[output.random]
+command = "python random.py"
+```
+
+### Optional backends
+
+If you enable a backend that isn't installed, the default behavior is to throw an error.
+This behavior can be changed by marking the backend as optional:
+
+```toml
+[output.wordcount]
+optional = true
+```
+
+This demotes the error to a warning.
+
+
+## HTML renderer options
+
+The HTML renderer has a variety of options detailed below.
+They should be specified in the `[output.html]` table of the `book.toml` file.
+
+```toml
+# Example book.toml file with all output options.
+[book]
+title = "Example book"
+authors = ["John Doe", "Jane Doe"]
+description = "The example book covers examples."
+
+[output.html]
+theme = "my-theme"
+default-theme = "light"
+preferred-dark-theme = "navy"
+curly-quotes = true
+mathjax-support = false
+copy-fonts = true
+additional-css = ["custom.css", "custom2.css"]
+additional-js = ["custom.js"]
+no-section-label = false
+git-repository-url = "https://github.com/rust-lang/mdBook"
+git-repository-icon = "fa-github"
+edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"
+site-url = "/example-book/"
+cname = "myproject.rs"
+input-404 = "not-found.md"
+```
+
+The following configuration options are available:
+
+- **theme:** mdBook comes with a default theme and all the resource files needed
+  for it. But if this option is set, mdBook will selectively overwrite the theme
+  files with the ones found in the specified folder.
+- **default-theme:** The theme color scheme to select by default in the
+  'Change Theme' dropdown. Defaults to `light`.
+- **preferred-dark-theme:** The default dark theme. This theme will be used if
+  the browser requests the dark version of the site via the
+  ['prefers-color-scheme'](https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme)
+  CSS media query. Defaults to `navy`.
+- **curly-quotes:** Convert straight quotes to curly quotes, except for those
+  that occur in code blocks and code spans. Defaults to `false`.
+- **mathjax-support:** Adds support for [MathJax](../mathjax.md). Defaults to
+  `false`.
+- **copy-fonts:** (**Deprecated**) If `true` (the default), mdBook uses its built-in fonts which are copied to the output directory.
+  If `false`, the built-in fonts will not be used.
+  This option is deprecated. If you want to define your own custom fonts,
+  create a `theme/fonts/fonts.css` file and store the fonts in the `theme/fonts/` directory.
+- **google-analytics:** This field has been deprecated and will be removed in a future release.
+  Use the `theme/head.hbs` file to add the appropriate Google Analytics code instead.
+- **additional-css:** If you need to slightly change the appearance of your book
+  without overwriting the whole style, you can specify a set of stylesheets that
+  will be loaded after the default ones where you can surgically change the
+  style.
+- **additional-js:** If you need to add some behaviour to your book without
+  removing the current behaviour, you can specify a set of JavaScript files that
+  will be loaded alongside the default one.
+- **no-section-label:** mdBook by defaults adds numeric section labels in the table of
+  contents column. For example, "1.", "2.1". Set this option to true to disable
+  those labels. Defaults to `false`.
+- **git-repository-url:**  A url to the git repository for the book. If provided
+  an icon link will be output in the menu bar of the book.
+- **git-repository-icon:** The FontAwesome icon class to use for the git
+  repository link. Defaults to `fa-github` which looks like <i class="fa fa-github"></i>.
+  If you are not using GitHub, another option to consider is `fa-code-fork` which looks like <i class="fa fa-code-fork"></i>.
+- **edit-url-template:** Edit url template, when provided shows a
+  "Suggest an edit" button (which looks like <i class="fa fa-edit"></i>) for directly jumping to editing the currently
+  viewed page. For e.g. GitHub projects set this to
+  `https://github.com/<owner>/<repo>/edit/master/{path}` or for
+  Bitbucket projects set it to
+  `https://bitbucket.org/<owner>/<repo>/src/master/{path}?mode=edit`
+  where {path} will be replaced with the full path of the file in the
+  repository.
+- **input-404:** The name of the markdown file used for missing files.
+  The corresponding output file will be the same, with the extension replaced with `html`.
+  Defaults to `404.md`.
+- **site-url:** The url where the book will be hosted. This is required to ensure
+  navigation links and script/css imports in the 404 file work correctly, even when accessing
+  urls in subdirectories. Defaults to `/`. If `site-url` is set,
+  make sure to use document relative links for your assets, meaning they should not start with `/`.
+- **cname:** The DNS subdomain or apex domain at which your book will be hosted.
+  This string will be written to a file named CNAME in the root of your site, as
+  required by GitHub Pages (see [*Managing a custom domain for your GitHub Pages
+  site*][custom domain]).
+
+[custom domain]: https://docs.github.com/en/github/working-with-github-pages/managing-a-custom-domain-for-your-github-pages-site
+
+### `[output.html.print]`
+
+The `[output.html.print]` table provides options for controlling the printable output.
+By default, mdBook will include an icon on the top right of the book (which looks like <i class="fa fa-print"></i>) that will print the book as a single page.
+
+```toml
+[output.html.print]
+enable = true    # include support for printable output
+page-break = true # insert page-break after each chapter
+```
+
+- **enable:** Enable print support. When `false`, all print support will not be
+  rendered. Defaults to `true`.
+- **page-break** Insert page breaks between chapters. Defaults to `true`.
+
+### `[output.html.fold]`
+
+The `[output.html.fold]` table provides options for controlling folding of the chapter listing in the navigation sidebar.
+
+```toml
+[output.html.fold]
+enable = false    # whether or not to enable section folding
+level = 0         # the depth to start folding
+```
+
+- **enable:** Enable section-folding. When off, all folds are open.
+  Defaults to `false`.
+- **level:** The higher the more folded regions are open. When level is 0, all
+  folds are closed. Defaults to `0`.
+
+### `[output.html.playground]`
+
+The `[output.html.playground]` table provides options for controlling Rust sample code blocks, and their integration with the [Rust Playground].
+
+[Rust Playground]: https://play.rust-lang.org/
+
+```toml
+[output.html.playground]
+editable = false         # allows editing the source code
+copyable = true          # include the copy button for copying code snippets
+copy-js = true           # includes the JavaScript for the code editor
+line-numbers = false     # displays line numbers for editable code
+runnable = true          # displays a run button for rust code
+```
+
+- **editable:** Allow editing the source code. Defaults to `false`.
+- **copyable:** Display the copy button on code snippets. Defaults to `true`.
+- **copy-js:** Copy JavaScript files for the editor to the output directory.
+  Defaults to `true`.
+- **line-numbers** Display line numbers on editable sections of code. Requires both `editable` and `copy-js` to be `true`. Defaults to `false`.
+- **runnable** Displays a run button for rust code snippets. Changing this to `false` will disable the run in playground feature globally. Defaults to `true`.
+
+[Ace]: https://ace.c9.io/
+
+### `[output.html.search]`
+
+The `[output.html.search]` table provides options for controlling the built-in text [search].
+mdBook must be compiled with the `search` feature enabled (on by default).
+
+[search]: ../../guide/reading.md#search
+
+```toml
+[output.html.search]
+enable = true            # enables the search feature
+limit-results = 30       # maximum number of search results
+teaser-word-count = 30   # number of words used for a search result teaser
+use-boolean-and = true   # multiple search terms must all match
+boost-title = 2          # ranking boost factor for matches in headers
+boost-hierarchy = 1      # ranking boost factor for matches in page names
+boost-paragraph = 1      # ranking boost factor for matches in text
+expand = true            # partial words will match longer terms
+heading-split-level = 3  # link results to heading levels
+copy-js = true           # include Javascript code for search
+```
+
+- **enable:** Enables the search feature. Defaults to `true`.
+- **limit-results:** The maximum number of search results. Defaults to `30`.
+- **teaser-word-count:** The number of words used for a search result teaser.
+  Defaults to `30`.
+- **use-boolean-and:** Define the logical link between multiple search words. If
+  true, all search words must appear in each result. Defaults to `false`.
+- **boost-title:** Boost factor for the search result score if a search word
+  appears in the header. Defaults to `2`.
+- **boost-hierarchy:** Boost factor for the search result score if a search word
+  appears in the hierarchy. The hierarchy contains all titles of the parent
+  documents and all parent headings. Defaults to `1`.
+- **boost-paragraph:** Boost factor for the search result score if a search word
+  appears in the text. Defaults to `1`.
+- **expand:** True if search should match longer results e.g. search `micro`
+  should match `microwave`. Defaults to `true`.
+- **heading-split-level:** Search results will link to a section of the document
+  which contains the result. Documents are split into sections by headings this
+  level or less. Defaults to `3`. (`### This is a level 3 heading`)
+- **copy-js:** Copy JavaScript files for the search implementation to the output
+  directory. Defaults to `true`.
+
+### `[output.html.redirect]`
+
+The `[output.html.redirect]` table provides a way to add redirects.
+This is useful when you move, rename, or remove a page to ensure that links to the old URL will go to the new location.
+
+```toml
+[output.html.redirect]
+"/appendices/bibliography.html" = "https://rustc-dev-guide.rust-lang.org/appendix/bibliography.html"
+"/other-installation-methods.html" = "../infra/other-installation-methods.html"
+```
+
+The table contains key-value pairs where the key is where the redirect file needs to be created, as an absolute path from the build directory, (e.g. `/appendices/bibliography.html`).
+The value can be any valid URI the browser should navigate to (e.g. `https://rust-lang.org/`, `/overview.html`, or `../bibliography.html`).
+
+This will generate an HTML page which will automatically redirect to the given location.
+Note that the source location does not support `#` anchor redirects.
+
+## Markdown Renderer
+
+The Markdown renderer will run preprocessors and then output the resulting
+Markdown. This is mostly useful for debugging preprocessors, especially in
+conjunction with `mdbook test` to see the Markdown that `mdbook` is passing
+to `rustdoc`.
+
+The Markdown renderer is included with `mdbook` but disabled by default.
+Enable it by adding an empty table to your `book.toml` as follows:
+
+```toml
+[output.markdown]
+```
+
+There are no configuration options for the Markdown renderer at this time;
+only whether it is enabled or disabled.
+
+See [the preprocessors documentation](preprocessors.md) for how to
+specify which preprocessors should run before the Markdown renderer.

guide/src/format/example.rs

@@ -0,0 +1,6 @@
+fn main() {
+    println!("Hello World!");
+#
+#     // You can even hide lines! :D
+#     println!("I am hidden! Expand the code snippet to see me");
+}

guide/src/format/images/rust-logo-blk.svg

@@ -0,0 +1 @@
+<svg height="144" width="144" xmlns="http://www.w3.org/2000/svg"><path d="m71.05 23.68c-26.06 0-47.27 21.22-47.27 47.27s21.22 47.27 47.27 47.27 47.27-21.22 47.27-47.27-21.22-47.27-47.27-47.27zm-.07 4.2a3.1 3.11 0 0 1 3.02 3.11 3.11 3.11 0 0 1 -6.22 0 3.11 3.11 0 0 1 3.2-3.11zm7.12 5.12a38.27 38.27 0 0 1 26.2 18.66l-3.67 8.28c-.63 1.43.02 3.11 1.44 3.75l7.06 3.13a38.27 38.27 0 0 1 .08 6.64h-3.93c-.39 0-.55.26-.55.64v1.8c0 4.24-2.39 5.17-4.49 5.4-2 .23-4.21-.84-4.49-2.06-1.18-6.63-3.14-8.04-6.24-10.49 3.85-2.44 7.85-6.05 7.85-10.87 0-5.21-3.57-8.49-6-10.1-3.42-2.25-7.2-2.7-8.22-2.7h-40.6a38.27 38.27 0 0 1 21.41-12.08l4.79 5.02c1.08 1.13 2.87 1.18 4 .09zm-44.2 23.02a3.11 3.11 0 0 1 3.02 3.11 3.11 3.11 0 0 1 -6.22 0 3.11 3.11 0 0 1 3.2-3.11zm74.15.14a3.11 3.11 0 0 1 3.02 3.11 3.11 3.11 0 0 1 -6.22 0 3.11 3.11 0 0 1 3.2-3.11zm-68.29.5h5.42v24.44h-10.94a38.27 38.27 0 0 1 -1.24-14.61l6.7-2.98c1.43-.64 2.08-2.31 1.44-3.74zm22.62.26h12.91c.67 0 4.71.77 4.71 3.8 0 2.51-3.1 3.41-5.65 3.41h-11.98zm0 17.56h9.89c.9 0 4.83.26 6.08 5.28.39 1.54 1.26 6.56 1.85 8.17.59 1.8 2.98 5.4 5.53 5.4h16.14a38.27 38.27 0 0 1 -3.54 4.1l-6.57-1.41c-1.53-.33-3.04.65-3.37 2.18l-1.56 7.28a38.27 38.27 0 0 1 -31.91-.15l-1.56-7.28c-.33-1.53-1.83-2.51-3.36-2.18l-6.43 1.38a38.27 38.27 0 0 1 -3.32-3.92h31.27c.35 0 .59-.06.59-.39v-11.06c0-.32-.24-.39-.59-.39h-9.15zm-14.43 25.33a3.11 3.11 0 0 1 3.02 3.11 3.11 3.11 0 0 1 -6.22 0 3.11 3.11 0 0 1 3.2-3.11zm46.05.14a3.11 3.11 0 0 1 3.02 3.11 3.11 3.11 0 0 1 -6.22 0 3.11 3.11 0 0 1 3.2-3.11z"/><path d="m115.68 70.95a44.63 44.63 0 0 1 -44.63 44.63 44.63 44.63 0 0 1 -44.63-44.63 44.63 44.63 0 0 1 44.63-44.63 44.63 44.63 0 0 1 44.63 44.63zm-.84-4.31 6.96 4.31-6.96 4.31 5.98 5.59-7.66 2.87 4.78 6.65-8.09 1.32 3.4 7.46-8.19-.29 1.88 7.98-7.98-1.88.29 8.19-7.46-3.4-1.32 8.09-6.65-4.78-2.87 7.66-5.59-5.98-4.31 6.96-4.31-6.96-5.59 5.98-2.87-7.66-6.65 4.78-1.32-8.09-7.46 3.4.29-8.19-7.98 1.88 1.88-7.98-8.19.29 3.4-7.46-8.09-1.32 4.78-6.65-7.66-2.87 5.98-5.59-6.96-4.31 6.96-4.31-5.98-5.59 7.66-2.87-4.78-6.65 8.09-1.32-3.4-7.46 8.19.29-1.88-7.98 7.98 1.88-.29-8.19 7.46 3.4 1.32-8.09 6.65 4.78 2.87-7.66 5.59 5.98 4.31-6.96 4.31 6.96 5.59-5.98 2.87 7.66 6.65-4.78 1.32 8.09 7.46-3.4-.29 8.19 7.98-1.88-1.88 7.98 8.19-.29-3.4 7.46 8.09 1.32-4.78 6.65 7.66 2.87z" fill-rule="evenodd" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="3"/></svg>

guide/src/format/markdown.md

@@ -0,0 +1,222 @@
+# Markdown
+
+mdBook's [parser](https://github.com/raphlinus/pulldown-cmark) adheres to the [CommonMark](https://commonmark.org/) specification with some extensions described below.
+You can take a quick [tutorial](https://commonmark.org/help/tutorial/),
+or [try out](https://spec.commonmark.org/dingus/) CommonMark in real time. A complete Markdown overview is out of scope for 
+this documentation, but below is a high level overview of some of the basics. For a more in-depth experience, check out the
+[Markdown Guide](https://www.markdownguide.org).
+
+## Text and Paragraphs
+
+Text is rendered relatively predictably: 
+
+```markdown
+Here is a line of text.
+
+This is a new line.
+```
+
+Will look like you might expect:
+
+Here is a line of text.
+
+This is a new line.
+
+## Headings
+
+Headings use the `#` marker and should be on a line by themselves. More `#` mean smaller headings:
+
+```markdown
+### A heading 
+
+Some text.
+
+#### A smaller heading 
+
+More text.
+```
+
+### A heading 
+
+Some text.
+
+#### A smaller heading 
+
+More text.
+
+## Lists
+
+Lists can be unordered or ordered. Ordered lists will order automatically:
+
+```markdown
+* milk
+* eggs
+* butter
+
+1. carrots
+1. celery
+1. radishes
+```
+
+* milk
+* eggs
+* butter
+
+1. carrots
+1. celery
+1. radishes
+
+## Links
+
+Linking to a URL or local file is easy:
+
+```markdown
+Use [mdBook](https://github.com/rust-lang/mdBook). 
+
+Read about [mdBook](mdBook.md).
+
+A bare url: <https://www.rust-lang.org>.
+```
+
+Use [mdBook](https://github.com/rust-lang/mdBook). 
+
+Read about [mdBook](mdBook.md).
+
+A bare url: <https://www.rust-lang.org>.
+
+----
+
+Relative links that end with `.md` will be converted to the `.html` extension.
+It is recommended to use `.md` links when possible.
+This is useful when viewing the Markdown file outside of mdBook, for example on GitHub or GitLab which render Markdown automatically.
+
+Links to `README.md` will be converted to `index.html`.
+This is done since some services like GitHub render README files automatically, but web servers typically expect the root file to be called `index.html`.
+
+You can link to individual headings with `#` fragments.
+For example, `mdbook.md#text-and-paragraphs` would link to the [Text and Paragraphs](#text-and-paragraphs) section above.
+The ID is created by transforming the heading such as converting to lowercase and replacing spaces with dashes.
+You can click on any heading and look at the URL in your browser to see what the fragment looks like.
+
+## Images
+
+Including images is simply a matter of including a link to them, much like in the _Links_ section above. The following markdown
+includes the Rust logo SVG image found in the `images` directory at the same level as this file:
+
+```markdown
+![The Rust Logo](images/rust-logo-blk.svg)
+```
+
+Produces the following HTML when built with mdBook:
+
+```html
+<p><img src="images/rust-logo-blk.svg" alt="The Rust Logo" /></p>
+```
+
+Which, of course displays the image like so:
+
+![The Rust Logo](images/rust-logo-blk.svg)
+
+## Extensions
+
+mdBook has several extensions beyond the standard CommonMark specification.
+
+### Strikethrough
+
+Text may be rendered with a horizontal line through the center by wrapping the
+text with two tilde characters on each side:
+
+```text
+An example of ~~strikethrough text~~.
+```
+
+This example will render as:
+
+> An example of ~~strikethrough text~~.
+
+This follows the [GitHub Strikethrough extension][strikethrough].
+
+### Footnotes
+
+A footnote generates a small numbered link in the text which when clicked
+takes the reader to the footnote text at the bottom of the item. The footnote
+label is written similarly to a link reference with a caret at the front. The
+footnote text is written like a link reference definition, with the text
+following the label. Example:
+
+```text
+This is an example of a footnote[^note].
+
+[^note]: This text is the contents of the footnote, which will be rendered
+    towards the bottom.
+```
+
+This example will render as:
+
+> This is an example of a footnote[^note].
+>
+> [^note]: This text is the contents of the footnote, which will be rendered
+>     towards the bottom.
+
+The footnotes are automatically numbered based on the order the footnotes are
+written.
+
+### Tables
+
+Tables can be written using pipes and dashes to draw the rows and columns of
+the table. These will be translated to HTML table matching the shape. Example:
+
+```text
+| Header1 | Header2 |
+|---------|---------|
+| abc     | def     |
+```
+
+This example will render similarly to this:
+
+| Header1 | Header2 |
+|---------|---------|
+| abc     | def     |
+
+See the specification for the [GitHub Tables extension][tables] for more
+details on the exact syntax supported.
+
+### Task lists
+
+Task lists can be used as a checklist of items that have been completed.
+Example:
+
+```md
+- [x] Complete task
+- [ ] Incomplete task
+```
+
+This will render as:
+
+> - [x] Complete task
+> - [ ] Incomplete task
+
+See the specification for the [task list extension] for more details.
+
+### Smart punctuation
+
+Some ASCII punctuation sequences will be automatically turned into fancy Unicode
+characters:
+
+| ASCII sequence | Unicode |
+|----------------|---------|
+| `--`           | –       |
+| `---`          | —       |
+| `...`          | …       |
+| `"`            | “ or ”, depending on context |
+| `'`            | ‘ or ’, depending on context |
+
+So, no need to manually enter those Unicode characters!
+
+This feature is disabled by default.
+To enable it, see the [`output.html.curly-quotes`] config option.
+
+[strikethrough]: https://github.github.com/gfm/#strikethrough-extension-
+[tables]: https://github.github.com/gfm/#tables-extension-
+[task list extension]: https://github.github.com/gfm/#task-list-items-extension-
+[`output.html.curly-quotes`]: configuration/renderers.md#html-renderer-options

guide/src/format/mathjax.md

@@ -0,0 +1,43 @@
+# MathJax Support
+
+mdBook has optional support for math equations through
+[MathJax](https://www.mathjax.org/).
+
+To enable MathJax, you need to add the `mathjax-support` key to your `book.toml`
+under the `output.html` section.
+
+```toml
+[output.html]
+mathjax-support = true
+```
+
+>**Note:** The usual delimiters MathJax uses are not yet supported. You can't
+currently use `$$ ... $$` as delimiters and the `\[ ... \]` delimiters need an
+extra backslash to work. Hopefully this limitation will be lifted soon.
+
+>**Note:** When you use double backslashes in MathJax blocks (for example in
+> commands such as `\begin{cases} \frac 1 2 \\ \frac 3 4 \end{cases}`) you need
+> to add _two extra_ backslashes (e.g., `\begin{cases} \frac 1 2 \\\\ \frac 3 4
+> \end{cases}`).
+
+
+### Inline equations
+Inline equations are delimited by `\\(` and `\\)`. So for example, to render the
+following inline equation \\( \int x dx = \frac{x^2}{2} + C \\) you would write
+the following:
+```
+\\( \int x dx = \frac{x^2}{2} + C \\)
+```
+
+### Block equations
+Block equations are delimited by `\\[` and `\\]`. To render the following
+equation
+
+\\[ \mu = \frac{1}{N} \sum_{i=0} x_i \\]
+
+
+you would write:
+
+```bash
+\\[ \mu = \frac{1}{N} \sum_{i=0} x_i \\]
+```

guide/src/format/mdbook.md

@@ -0,0 +1,276 @@
+# mdBook-specific features
+
+## Hiding code lines
+
+There is a feature in mdBook that lets you hide code lines by prepending them
+with a `#` [like you would with Rustdoc][rustdoc-hide].
+This currently only works with Rust language code blocks.
+
+[rustdoc-hide]: https://doc.rust-lang.org/stable/rustdoc/documentation-tests.html#hiding-portions-of-the-example
+
+```bash
+# fn main() {
+    let x = 5;
+    let y = 6;
+
+    println!("{}", x + y);
+# }
+```
+
+Will render as
+
+```rust
+# fn main() {
+    let x = 5;
+    let y = 6;
+
+    println!("{}", x + y);
+# }
+```
+
+The code block has an eyeball icon (<i class="fa fa-eye"></i>) which will toggle the visibility of the hidden lines.
+
+## Rust Playground
+
+Rust language code blocks will automatically get a play button (<i class="fa fa-play"></i>) which will execute the code and display the output just below the code block.
+This works by sending the code to the [Rust Playground].
+
+```rust
+println!("Hello, World!");
+```
+
+If there is no `main` function, then the code is automatically wrapped inside one.
+
+If you wish to disable the play button for a code block, you can include the `noplayground` option on the code block like this:
+
+~~~markdown
+```rust,noplayground
+let mut name = String::new();
+std::io::stdin().read_line(&mut name).expect("failed to read line");
+println!("Hello {}!", name);
+```
+~~~
+
+Or, if you wish to disable the play button for all code blocks in your book, you can write the config to the `book.toml` like this.
+
+```toml
+[output.html.playground]
+runnable = false
+```
+
+## Rust code block attributes
+
+Additional attributes can be included in Rust code blocks with comma, space, or tab-separated terms just after the language term. For example:
+
+~~~markdown
+```rust,ignore
+# This example won't be tested.
+panic!("oops!");
+```
+~~~
+
+These are particularly important when using [`mdbook test`] to test Rust examples.
+These use the same attributes as [rustdoc attributes], with a few additions:
+
+* `editable` — Enables the [editor].
+* `noplayground` — Removes the play button, but will still be tested.
+* `mdbook-runnable` — Forces the play button to be displayed.
+  This is intended to be combined with the `ignore` attribute for examples that should not be tested, but you want to allow the reader to run.
+* `ignore` — Will not be tested and no play button is shown, but it is still highlighted as Rust syntax.
+* `should_panic` — When executed, it should produce a panic.
+* `no_run` — The code is compiled when tested, but it is not run.
+  The play button is also not shown.
+* `compile_fail` — The code should fail to compile.
+* `edition2015`, `edition2018`, `edition2021` — Forces the use of a specific Rust edition.
+  See [`rust.edition`] to set this globally.
+
+[`mdbook test`]: ../cli/test.md
+[rustdoc attributes]: https://doc.rust-lang.org/rustdoc/documentation-tests.html#attributes
+[editor]: theme/editor.md
+[`rust.edition`]: configuration/general.md#rust-options
+
+## Including files
+
+With the following syntax, you can include files into your book:
+
+```hbs
+\{{#include file.rs}}
+```
+
+The path to the file has to be relative from the current source file.
+
+mdBook will interpret included files as Markdown. Since the include command
+is usually used for inserting code snippets and examples, you will often
+wrap the command with ```` ``` ```` to display the file contents without
+interpreting them.
+
+````hbs
+```
+\{{#include file.rs}}
+```
+````
+
+## Including portions of a file
+Often you only need a specific part of the file, e.g. relevant lines for an
+example. We support four different modes of partial includes:
+
+```hbs
+\{{#include file.rs:2}}
+\{{#include file.rs::10}}
+\{{#include file.rs:2:}}
+\{{#include file.rs:2:10}}
+```
+
+The first command only includes the second line from file `file.rs`. The second
+command includes all lines up to line 10, i.e. the lines from 11 till the end of
+the file are omitted. The third command includes all lines from line 2, i.e. the
+first line is omitted. The last command includes the excerpt of `file.rs`
+consisting of lines 2 to 10.
+
+To avoid breaking your book when modifying included files, you can also
+include a specific section using anchors instead of line numbers.
+An anchor is a pair of matching lines. The line beginning an anchor must
+match the regex `ANCHOR:\s*[\w_-]+` and similarly the ending line must match
+the regex `ANCHOR_END:\s*[\w_-]+`. This allows you to put anchors in
+any kind of commented line.
+
+Consider the following file to include:
+```rs
+/* ANCHOR: all */
+
+// ANCHOR: component
+struct Paddle {
+    hello: f32,
+}
+// ANCHOR_END: component
+
+////////// ANCHOR: system
+impl System for MySystem { ... }
+////////// ANCHOR_END: system
+
+/* ANCHOR_END: all */
+```
+
+Then in the book, all you have to do is:
+````hbs
+Here is a component:
+```rust,no_run,noplayground
+\{{#include file.rs:component}}
+```
+
+Here is a system:
+```rust,no_run,noplayground
+\{{#include file.rs:system}}
+```
+
+This is the full file.
+```rust,no_run,noplayground
+\{{#include file.rs:all}}
+```
+````
+
+Lines containing anchor patterns inside the included anchor are ignored.
+
+## Including a file but initially hiding all except specified lines
+
+The `rustdoc_include` helper is for including code from external Rust files that contain complete
+examples, but only initially showing particular lines specified with line numbers or anchors in the
+same way as with `include`.
+
+The lines not in the line number range or between the anchors will still be included, but they will
+be prefaced with `#`. This way, a reader can expand the snippet to see the complete example, and
+Rustdoc will use the complete example when you run `mdbook test`.
+
+For example, consider a file named `file.rs` that contains this Rust program:
+
+```rust
+fn main() {
+    let x = add_one(2);
+    assert_eq!(x, 3);
+}
+
+fn add_one(num: i32) -> i32 {
+    num + 1
+}
+```
+
+We can include a snippet that initially shows only line 2 by using this syntax:
+
+````hbs
+To call the `add_one` function, we pass it an `i32` and bind the returned value to `x`:
+
+```rust
+\{{#rustdoc_include file.rs:2}}
+```
+````
+
+This would have the same effect as if we had manually inserted the code and hidden all but line 2
+using `#`:
+
+````hbs
+To call the `add_one` function, we pass it an `i32` and bind the returned value to `x`:
+
+```rust
+# fn main() {
+    let x = add_one(2);
+#     assert_eq!(x, 3);
+# }
+#
+# fn add_one(num: i32) -> i32 {
+#     num + 1
+# }
+```
+````
+
+That is, it looks like this (click the "expand" icon to see the rest of the file):
+
+```rust
+# fn main() {
+    let x = add_one(2);
+#     assert_eq!(x, 3);
+# }
+#
+# fn add_one(num: i32) -> i32 {
+#     num + 1
+# }
+```
+
+## Inserting runnable Rust files
+
+With the following syntax, you can insert runnable Rust files into your book:
+
+```hbs
+\{{#playground file.rs}}
+```
+
+The path to the Rust file has to be relative from the current source file.
+
+When play is clicked, the code snippet will be sent to the [Rust Playground] to be
+compiled and run. The result is sent back and displayed directly underneath the
+code.
+
+Here is what a rendered code snippet looks like:
+
+{{#playground example.rs}}
+
+Any additional values passed after the filename will be included as attributes of the code block.
+For example `\{{#playground example.rs editable}}` will create the code block like the following:
+
+~~~markdown
+```rust,editable
+# Contents of example.rs here.
+```
+~~~
+
+And the `editable` attribute will enable the [editor] as described at [Rust code block attributes](#rust-code-block-attributes).
+
+[Rust Playground]: https://play.rust-lang.org/
+
+## Controlling page \<title\>
+
+A chapter can set a \<title\> that is different from its entry in the table of
+contents (sidebar) by including a `\{{#title ...}}` near the top of the page.
+
+```hbs
+\{{#title My Title}}
+```

guide/src/format/summary.md

@@ -0,0 +1,99 @@
+# SUMMARY.md
+
+The summary file is used by mdBook to know what chapters to include, in what
+order they should appear, what their hierarchy is and where the source files
+are. Without this file, there is no book.
+
+This markdown file must be named `SUMMARY.md`. Its formatting
+is very strict and must follow the structure outlined below to allow for easy
+parsing. Any element not specified below, be it formatting or textual, is likely
+to be ignored at best, or may cause an error when attempting to build the book.
+
+### Structure
+
+1. ***Title*** - While optional, it's common practice to begin with a title, generally <code
+   class="language-markdown"># Summary</code>. This is ignored by the parser however, and
+   can be omitted.
+   ```markdown
+   # Summary
+   ```
+
+1. ***Prefix Chapter*** - Before the main numbered chapters, prefix chapters can be added
+   that will not be numbered. This is useful for forewords,
+   introductions, etc. There are, however, some constraints. Prefix chapters cannot be
+   nested; they should all be on the root level. And you cannot add
+   prefix chapters once you have added numbered chapters.
+   ```markdown
+   [A Prefix Chapter](relative/path/to/markdown.md)
+
+   - [First Chapter](relative/path/to/markdown2.md)
+   ```
+
+1. ***Part Title*** - Headers can be used as a title for the following numbered
+   chapters. This can be used to logically separate different sections
+   of the book. The title is rendered as unclickable text.
+   Titles are optional, and the numbered chapters can be broken into as many
+   parts as desired.
+   ```markdown
+   # My Part Title
+
+   - [First Chapter](relative/path/to/markdown.md)
+   ```
+
+1. ***Numbered Chapter*** - Numbered chapters outline the main content of the book
+   and can be nested, resulting in a nice hierarchy
+   (chapters, sub-chapters, etc.).
+   ```markdown
+   # Title of Part
+
+   - [First Chapter](relative/path/to/markdown.md)
+   - [Second Chapter](relative/path/to/markdown2.md)
+      - [Sub Chapter](relative/path/to/markdown3.md)
+
+   # Title of Another Part
+
+   - [Another Chapter](relative/path/to/markdown4.md)
+   ```
+   Numbered chapters can be denoted with either `-` or `*` (do not mix delimiters). 
+   
+1. ***Suffix Chapter*** - Like prefix chapters, suffix chapters are unnumbered, but they come after 
+   numbered chapters.
+   ```markdown
+   - [Last Chapter](relative/path/to/markdown.md)
+
+   [Title of Suffix Chapter](relative/path/to/markdown2.md)
+   ```
+
+1. ***Draft chapters*** - Draft chapters are chapters without a file and thus content.
+   The purpose of a draft chapter is to signal future chapters still to be written.
+   Or when still laying out the structure of the book to avoid creating the files
+   while you are still changing the structure of the book a lot.
+   Draft chapters will be rendered in the HTML renderer as disabled links in the table
+   of contents, as you can see for the next chapter in the table of contents on the left.
+   Draft chapters are written like normal chapters but without writing the path to the file.
+   ```markdown
+   - [Draft Chapter]()
+   ```
+
+1. ***Separators*** - Separators can be added before, in between, and after any other element. They result
+   in an HTML rendered line in the built table of contents.  A separator is
+   a line containing exclusively dashes and at least three of them: `---`.
+   ```markdown
+   # My Part Title
+   
+   [A Prefix Chapter](relative/path/to/markdown.md)
+
+   ---
+
+   - [First Chapter](relative/path/to/markdown2.md)
+   ```
+  
+
+### Example
+
+Below is the markdown source for the `SUMMARY.md` for this guide, with the resulting table
+of contents as rendered to the left.
+
+```markdown
+{{#include ../SUMMARY.md}}
+```

guide/src/format/theme/README.md

@@ -0,0 +1,52 @@
+# Theme
+
+The default renderer uses a [handlebars](http://handlebarsjs.com/) template to
+render your markdown files and comes with a default theme included in the mdBook
+binary.
+
+The theme is totally customizable, you can selectively replace every file from
+the theme by your own by adding a `theme` directory next to `src` folder in your
+project root. Create a new file with the name of the file you want to override
+and now that file will be used instead of the default file.
+
+Here are the files you can override:
+
+- **_index.hbs_** is the handlebars template.
+- **_head.hbs_** is appended to the HTML `<head>` section.
+- **_header.hbs_** content is appended on top of every book page.
+- **_css/_** contains the CSS files for styling the book.
+    - **_css/chrome.css_** is for UI elements.
+    - **_css/general.css_** is the base styles.
+    - **_css/print.css_** is the style for printer output.
+    - **_css/variables.css_** contains variables used in other CSS files.
+- **_book.js_** is mostly used to add client side functionality, like hiding /
+  un-hiding the sidebar, changing the theme, ...
+- **_highlight.js_** is the JavaScript that is used to highlight code snippets,
+  you should not need to modify this.
+- **_highlight.css_** is the theme used for the code highlighting.
+- **_favicon.svg_** and **_favicon.png_** the favicon that will be used. The SVG
+  version is used by [newer browsers].
+- **fonts/fonts.css** contains the definition of which fonts to load.
+  Custom fonts can be included in the `fonts` directory.
+
+Generally, when you want to tweak the theme, you don't need to override all the
+files. If you only need changes in the stylesheet, there is no point in
+overriding all the other files. Because custom files take precedence over
+built-in ones, they will not get updated with new fixes / features.
+
+**Note:** When you override a file, it is possible that you break some
+functionality. Therefore I recommend to use the file from the default theme as
+template and only add / modify what you need. You can copy the default theme
+into your source directory automatically by using `mdbook init --theme` and just
+remove the files you don't want to override.
+
+`mdbook init --theme` will not create every file listed above.
+Some files, such as `head.hbs`, do not have built-in equivalents.
+Just create the file if you need it.
+
+If you completely replace all built-in themes, be sure to also set
+[`output.html.preferred-dark-theme`] in the config, which defaults to the
+built-in `navy` theme.
+
+[`output.html.preferred-dark-theme`]: ../configuration/renderers.md#html-renderer-options
+[newer browsers]: https://caniuse.com/#feat=link-icon-svg

guide/src/format/theme/editor.md

@@ -0,0 +1,48 @@
+# Editor
+
+In addition to providing runnable code playgrounds, mdBook optionally allows them
+to be editable. In order to enable editable code blocks, the following needs to
+be added to the ***book.toml***:
+
+```toml
+[output.html.playground]
+editable = true
+```
+
+To make a specific block available for editing, the attribute `editable` needs
+to be added to it:
+
+~~~markdown
+```rust,editable
+fn main() {
+    let number = 5;
+    print!("{}", number);
+}
+```
+~~~
+
+The above will result in this editable playground:
+
+```rust,editable
+fn main() {
+    let number = 5;
+    print!("{}", number);
+}
+```
+
+Note the new `Undo Changes` button in the editable playgrounds.
+
+## Customizing the Editor
+
+By default, the editor is the [Ace](https://ace.c9.io/) editor, but, if desired,
+the functionality may be overridden by providing a different folder:
+
+```toml
+[output.html.playground]
+editable = true
+editor = "/path/to/editor"
+```
+
+Note that for the editor changes to function correctly, the `book.js` inside of
+the `theme` folder will need to be overridden as it has some couplings with the
+default Ace editor.

guide/src/format/theme/index-hbs.md

@@ -0,0 +1,101 @@
+# index.hbs
+
+`index.hbs` is the handlebars template that is used to render the book. The
+markdown files are processed to html and then injected in that template.
+
+If you want to change the layout or style of your book, chances are that you
+will have to modify this template a little bit. Here is what you need to know.
+
+## Data
+
+A lot of data is exposed to the handlebars template with the "context". In the
+handlebars template you can access this information by using
+
+```handlebars
+{{name_of_property}}
+```
+
+Here is a list of the properties that are exposed:
+
+- ***language*** Language of the book in the form `en`, as specified in `book.toml` (if not specified, defaults to `en`). To use in <code
+  class="language-html">\<html lang="{{ language }}"></code> for example.
+- ***title*** Title used for the current page. This is identical to `{{ chapter_title }} - {{ book_title }}` unless `book_title` is not set in which case it just defaults to the `chapter_title`.
+- ***book_title*** Title of the book, as specified in `book.toml`
+- ***chapter_title*** Title of the current chapter, as listed in `SUMMARY.md`
+
+- ***path*** Relative path to the original markdown file from the source
+  directory
+- ***content*** This is the rendered markdown.
+- ***path_to_root*** This is a path containing exclusively `../`'s that points
+  to the root of the book from the current file. Since the original directory
+  structure is maintained, it is useful to prepend relative links with this
+  `path_to_root`.
+
+- ***chapters*** Is an array of dictionaries of the form
+  ```json
+  {"section": "1.2.1", "name": "name of this chapter", "path": "dir/markdown.md"}
+  ```
+  containing all the chapters of the book. It is used for example to construct
+  the table of contents (sidebar).
+
+## Handlebars Helpers
+
+In addition to the properties you can access, there are some handlebars helpers
+at your disposal.
+
+### 1. toc
+
+The toc helper is used like this
+
+```handlebars
+{{#toc}}{{/toc}}
+```
+
+and outputs something that looks like this, depending on the structure of your
+book
+
+```html
+<ul class="chapter">
+    <li><a href="link/to/file.html">Some chapter</a></li>
+    <li>
+        <ul class="section">
+            <li><a href="link/to/other_file.html">Some other Chapter</a></li>
+        </ul>
+    </li>
+</ul>
+```
+
+If you would like to make a toc with another structure, you have access to the
+chapters property containing all the data. The only limitation at the moment
+is that you would have to do it with JavaScript instead of with a handlebars
+helper.
+
+```html
+<script>
+var chapters = {{chapters}};
+// Processing here
+</script>
+```
+
+### 2. previous / next
+
+The previous and next helpers expose a `link` and `name` property to the
+previous and next chapters.
+
+They are used like this
+
+```handlebars
+{{#previous}}
+    <a href="{{link}}" class="nav-chapters previous">
+        <i class="fa fa-angle-left"></i>
+    </a>
+{{/previous}}
+```
+
+The inner html will only be rendered if the previous / next chapter exists.
+Of course the inner html can be changed to your liking.
+
+------
+
+*If you would like other properties or helpers exposed, please [create a new
+issue](https://github.com/rust-lang/mdBook/issues)*

guide/src/format/theme/syntax-highlighting.md

@@ -0,0 +1,121 @@
+# Syntax Highlighting
+
+mdBook uses [Highlight.js](https://highlightjs.org) with a custom theme
+for syntax highlighting.
+
+Automatic language detection has been turned off, so you will probably want to
+specify the programming language you use like this:
+
+~~~markdown
+```rust
+fn main() {
+    // Some code
+}
+```
+~~~
+
+## Supported languages
+
+These languages are supported by default, but you can add more by supplying
+your own `highlight.js` file:
+
+- apache
+- armasm
+- bash
+- c
+- coffeescript
+- cpp
+- csharp
+- css
+- d
+- diff
+- go
+- handlebars
+- haskell
+- http
+- ini
+- java
+- javascript
+- json
+- julia
+- kotlin
+- less
+- lua
+- makefile
+- markdown
+- nginx
+- objectivec
+- perl
+- php
+- plaintext
+- properties
+- python
+- r
+- ruby
+- rust
+- scala
+- scss
+- shell
+- sql
+- swift
+- typescript
+- x86asm
+- xml
+- yaml
+
+## Custom theme
+Like the rest of the theme, the files used for syntax highlighting can be
+overridden with your own.
+
+- ***highlight.js*** normally you shouldn't have to overwrite this file, unless
+  you want to use a more recent version.
+- ***highlight.css*** theme used by highlight.js for syntax highlighting.
+
+If you want to use another theme for `highlight.js` download it from their
+website, or make it yourself, rename it to `highlight.css` and put it in
+the `theme` folder of your book.
+
+Now your theme will be used instead of the default theme.
+
+## Hiding code lines
+
+There is a feature in mdBook that lets you hide code lines by prepending them
+with a `#`.
+
+
+```bash
+# fn main() {
+    let x = 5;
+    let y = 6;
+
+    println!("{}", x + y);
+# }
+```
+
+Will render as
+
+```rust
+# fn main() {
+    let x = 5;
+    let y = 7;
+
+    println!("{}", x + y);
+# }
+```
+
+**At the moment, this only works for code examples that are annotated with
+`rust`. Because it would collide with semantics of some programming languages.
+In the future, we want to make this configurable through the `book.toml` so that
+everyone can benefit from it.**
+
+
+## Improve default theme
+
+If you think the default theme doesn't look quite right for a specific language,
+or could be improved, feel free to [submit a new
+issue](https://github.com/rust-lang/mdBook/issues) explaining what you
+have in mind and I will take a look at it.
+
+You could also create a pull-request with the proposed improvements.
+
+Overall the theme should be light and sober, without too many flashy colors.

guide/src/guide/README.md

@@ -0,0 +1,7 @@
+# User Guide
+
+This user guide provides an introduction to basic concepts of using mdBook.
+
+- [Installation](installation.md)
+- [Reading Books](reading.md)
+- [Creating a Book](creating.md)

guide/src/guide/creating.md

@@ -0,0 +1,109 @@
+# Creating a Book
+
+Once you have the `mdbook` CLI tool installed, you can use it to create and render a book.
+
+## Initializing a book
+
+The `mdbook init` command will create a new directory containing an empty book for you to get started.
+Give it the name of the directory that you want to create:
+
+```sh
+mdbook init my-first-book
+```
+
+It will ask a few questions before generating the book.
+After answering the questions, you can change the current directory into the new book:
+
+```sh
+cd my-first-book
+```
+
+There are several ways to render a book, but one of the easiest methods is to use the `serve` command, which will build your book and start a local webserver:
+
+```sh
+mdbook serve --open
+```
+
+The `--open` option will open your default web browser to view your new book.
+You can leave the server running even while you edit the content of the book, and `mdbook` will automatically rebuild the output *and* automatically refresh your web browser.
+
+Check out the [CLI Guide](../cli/index.html) for more information about other `mdbook` commands and CLI options.
+
+## Anatomy of a book
+
+A book is built from several files which define the settings and layout of the book.
+
+### `book.toml`
+
+In the root of your book, there is a `book.toml` file which contains settings for describing how to build your book.
+This is written in the [TOML markup language](https://toml.io/).
+The default settings are usually good enough to get you started.
+When you are interested in exploring more features and options that mdBook provides, check out the [Configuration chapter](../format/configuration/index.html) for more details.
+
+A very basic `book.toml` can be as simple as this:
+
+```toml
+[book]
+title = "My First Book"
+```
+
+### `SUMMARY.md`
+
+The next major part of a book is the summary file located at `src/SUMMARY.md`.
+This file contains a list of all the chapters in the book.
+Before a chapter can be viewed, it must be added to this list.
+
+Here's a basic summary file with a few chapters:
+
+```md
+# Summary
+
+[Introduction](README.md)
+
+- [My First Chapter](my-first-chapter.md)
+- [Nested example](nested/README.md)
+    - [Sub-chapter](nested/sub-chapter.md)
+```
+
+Try opening up `src/SUMMARY.md` in your editor and adding a few chapters.
+If any of the chapter files do not exist, `mdbook` will automatically create them for you.
+
+For more details on other formatting options for the summary file, check out the [Summary chapter](../format/summary.md).
+
+### Source files
+
+The content of your book is all contained in the `src` directory.
+Each chapter is a separate Markdown file.
+Typically, each chapter starts with a level 1 heading with the title of the chapter.
+
+```md
+# My First Chapter
+
+Fill out your content here.
+```
+
+The precise layout of the files is up to you.
+The organization of the files will correspond to the HTML files generated, so keep in mind that the file layout is part of the URL of each chapter.
+
+While the `mdbook serve` command is running, you can open any of the chapter files and start editing them.
+Each time you save the file, `mdbook` will rebuild the book and refresh your web browser.
+
+Check out the [Markdown chapter](../format/markdown.md) for more information on formatting the content of your chapters.
+
+All other files in the `src` directory will be included in the output.
+So if you have images or other static files, just include them somewhere in the `src` directory.
+
+## Publishing a book
+
+Once you've written your book, you may want to host it somewhere for others to view.
+The first step is to build the output of the book.
+This can be done with the `mdbook build` command in the same directory where the `book.toml` file is located:
+
+```sh
+mdbook build
+```
+
+This will generate a directory named `book` which contains the HTML content of your book.
+You can then place this directory on any web server to host it.
+
+For more information about publishing and deploying, check out the [Continuous Integration chapter](../continuous-integration.md) for more.

guide/src/guide/installation.md

@@ -0,0 +1,52 @@
+# Installation
+
+There are multiple ways to install the mdBook CLI tool.
+Choose any one of the methods below that best suit your needs.
+If you are installing mdBook for automatic deployment, check out the [continuous integration] chapter for more examples on how to install.
+
+[continuous integration]: ../continuous-integration.md
+
+## Pre-compiled binaries
+
+Executable binaries are available for download on the [GitHub Releases page][releases].
+Download the binary for your platform (Windows, macOS, or Linux) and extract the archive.
+The archive contains an `mdbook` executable which you can run to build your books.
+
+To make it easier to run, put the path to the binary into your `PATH`.
+
+[releases]: https://github.com/rust-lang/mdBook/releases
+
+## Build from source using Rust
+
+To build the `mdbook` executable from source, you will first need to install Rust and Cargo.
+Follow the instructions on the [Rust installation page].
+mdBook currently requires at least Rust version 1.60.
+
+Once you have installed Rust, the following command can be used to build and install mdBook:
+
+```sh
+cargo install mdbook
+```
+
+This will automatically download mdBook from [crates.io], build it, and install it in Cargo's global binary directory (`~/.cargo/bin/` by default).
+
+To uninstall, run the command `cargo uninstall mdbook`.
+
+[Rust installation page]: https://www.rust-lang.org/tools/install
+[crates.io]: https://crates.io/
+
+### Installing the latest master version
+
+The version published to crates.io will ever so slightly be behind the version hosted on GitHub.
+If you need the latest version you can build the git version of mdBook yourself.
+Cargo makes this ***super easy***!
+
+```sh
+cargo install --git https://github.com/rust-lang/mdBook.git mdbook
+```
+
+Again, make sure to add the Cargo bin directory to your `PATH`.
+
+If you are interested in making modifications to mdBook itself, check out the [Contributing Guide] for more information.
+
+[Contributing Guide]: https://github.com/rust-lang/mdBook/blob/master/CONTRIBUTING.md

guide/src/guide/reading.md

@@ -0,0 +1,74 @@
+# Reading Books
+
+This chapter gives an introduction on how to interact with a book produced by mdBook.
+This assumes you are reading an HTML book.
+The options and formatting will be different for other output formats such as PDF.
+
+A book is organized into *chapters*.
+Each chapter is a separate page.
+Chapters can be nested into a hierarchy of sub-chapters.
+Typically, each chapter will be organized into a series of *headings* to subdivide a chapter.
+
+## Navigation
+
+There are several methods for navigating through the chapters of a book.
+
+The **sidebar** on the left provides a list of all chapters.
+Clicking on any of the chapter titles will load that page.
+
+The sidebar may not automatically appear if the window is too narrow, particularly on mobile displays.
+In that situation, the menu icon (three horizontal bars) at the top-left of the page can be pressed to open and close the sidebar.
+
+The **arrow buttons** at the bottom of the page can be used to navigate to the previous or the next chapter.
+
+The **left and right arrow keys** on the keyboard can be used to navigate to the previous or the next chapter.
+
+## Top menu bar
+
+The menu bar at the top of the page provides some icons for interacting with the book.
+The icons displayed will depend on the settings of how the book was generated.
+
+| Icon | Description |
+|------|-------------|
+| <i class="fa fa-bars"></i> | Opens and closes the chapter listing sidebar. |
+| <i class="fa fa-paint-brush"></i> | Opens a picker to choose a different color theme. |
+| <i class="fa fa-search"></i> | Opens a search bar for searching within the book. |
+| <i class="fa fa-print"></i> | Instructs the web browser to print the entire book. |
+| <i class="fa fa-github"></i> | Opens a link to the website that hosts the source code of the book. |
+| <i class="fa fa-edit"></i> | Opens a page to directly edit the source of the page you are currently reading. |
+
+Tapping the menu bar will scroll the page to the top.
+
+## Search
+
+Each book has a built-in search system.
+Pressing the search icon (<i class="fa fa-search"></i>) in the menu bar, or pressing the `S` key on the keyboard will open an input box for entering search terms.
+Typing some terms will show matching chapters and sections in real time.
+
+Clicking any of the results will jump to that section.
+The up and down arrow keys can be used to navigate the results, and enter will open the highlighted section.
+
+After loading a search result, the matching search terms will be highlighted in the text.
+Clicking a highlighted word or pressing the `Esc` key will remove the highlighting.
+
+## Code blocks
+
+mdBook books are often used for programming projects, and thus support highlighting code blocks and samples.
+Code blocks may contain several different icons for interacting with them:
+
+| Icon | Description |
+|------|-------------|
+| <i class="fa fa-copy"></i> | Copies the code block into your local clipboard, to allow pasting into another application. |
+| <i class="fa fa-play"></i> | For Rust code examples, this will execute the sample code and display the compiler output just below the example (see [playground]). |
+| <i class="fa fa-eye"></i> | For Rust code examples, this will toggle visibility of "hidden" lines. Sometimes, larger examples will hide lines which are not particularly relevant to what is being illustrated (see [hiding code lines]). |
+| <i class="fa fa-history"></i> | For [editable code examples][editor], this will undo any changes you have made. |
+
+Here's an example:
+
+```rust
+println!("Hello, World!");
+```
+
+[editor]: ../format/theme/editor.md
+[playground]: ../format/mdbook.md#rust-playground
+[hiding code lines]: ../format/mdbook.md#hiding-code-lines

guide/src/misc/contributors.md

@@ -0,0 +1,24 @@
+# Contributors
+
+Here is a list of the contributors who have helped improving mdBook. Big
+shout-out to them!
+
+- [mdinger](https://github.com/mdinger)
+- Kevin ([kbknapp](https://github.com/kbknapp))
+- Steve Klabnik ([steveklabnik](https://github.com/steveklabnik))
+- Adam Solove ([asolove](https://github.com/asolove))
+- Wayne Nilsen ([waynenilsen](https://github.com/waynenilsen))
+- [funnkill](https://github.com/funkill)
+- Fu Gangqiang ([FuGangqiang](https://github.com/FuGangqiang))
+- [Michael-F-Bryan](https://github.com/Michael-F-Bryan)
+- Chris Spiegel ([cspiegel](https://github.com/cspiegel))
+- [projektir](https://github.com/projektir)
+- [Phaiax](https://github.com/Phaiax)
+- Matt Ickstadt ([mattico](https://github.com/mattico))
+- Weihang Lo ([weihanglo](https://github.com/weihanglo))
+- Avision Ho ([avisionh](https://github.com/avisionh))
+- Vivek Akupatni ([apatniv](https://github.com/apatniv))
+- Eric Huss ([ehuss](https://github.com/ehuss))
+- Josh Rotenberg ([joshrotenberg](https://github.com/joshrotenberg))
+
+If you feel you're missing from this list, feel free to add yourself in a PR.

release.toml

@@ -0,0 +1,3 @@
+sign-commit = true
+push-remote = "origin"
+tag-prefix = "v"

src/bin/mdbook.rs

@@ -1,228 +0,0 @@
-#[macro_use]
-extern crate mdbook;
-#[macro_use]
-extern crate clap;
-extern crate crossbeam;
-
-// Dependencies for the Watch feature
-#[cfg(feature = "watch")]
-extern crate notify;
-#[cfg(feature = "watch")]
-extern crate time;
-
-
-use std::env;
-use std::error::Error;
-use std::io::{self, Write};
-use std::path::{Path, PathBuf};
-
-use clap::{App, ArgMatches, SubCommand};
-
-// Uses for the Watch feature
-#[cfg(feature = "watch")]
-use notify::Watcher;
-#[cfg(feature = "watch")]
-use std::sync::mpsc::channel;
-
-
-use mdbook::MDBook;
-
-const NAME: &'static str = "mdbook";
-
-fn main() {
-    // Create a list of valid arguments and sub-commands
-    let matches = App::new(NAME)
-                    .about("Create a book in form of a static website from markdown files")
-                    .author("Mathieu David <mathieudavid@mathieudavid.org>")
-                    // Get the version from our Cargo.toml using clap's crate_version!() macro
-                    .version(&*format!("v{}", crate_version!()))
-                    .subcommand_required(true)
-                    .after_help("For more information about a specific command, try `mdbook <command> --help`")
-                    .subcommand(SubCommand::with_name("init")
-                        .about("Create boilerplate structure and files in the directory")
-                        // the {n} denotes a newline which will properly aligned in all help messages
-                        .arg_from_usage("[dir] 'A directory for your book{n}(Defaults to Current Directory when ommitted)'")
-                        .arg_from_usage("--theme 'Copies the default theme into your source folder'")
-                        .arg_from_usage("--force 'skip confirmation prompts'"))
-                    .subcommand(SubCommand::with_name("build")
-                        .about("Build the book from the markdown files")
-                        .arg_from_usage("[dir] 'A directory for your book{n}(Defaults to Current Directory when ommitted)'"))
-                    .subcommand(SubCommand::with_name("watch")
-                        .about("Watch the files for changes")
-                        .arg_from_usage("[dir] 'A directory for your book{n}(Defaults to Current Directory when ommitted)'"))
-                    .subcommand(SubCommand::with_name("test")
-                        .about("Test that code samples compile"))
-                    .get_matches();
-
-    // Check which subcomamnd the user ran...
-    let res = match matches.subcommand() {
-        ("init", Some(sub_matches))  => init(sub_matches),
-        ("build", Some(sub_matches)) => build(sub_matches),
-        #[cfg(feature = "watch")]
-        ("watch", Some(sub_matches)) => watch(sub_matches),
-        ("test", Some(sub_matches)) => test(sub_matches),
-        (_, _)                       => unreachable!()
-    };
-
-    if let Err(e) = res {
-        writeln!(&mut io::stderr(), "An error occured:\n{}", e).ok();
-    }
-}
-
-
-// Simple function that user comfirmation
-fn confirm() -> bool {
-    io::stdout().flush().unwrap();
-    let mut s = String::new();
-    io::stdin().read_line(&mut s).ok();
-    match &*s.trim() {
-        "Y" | "y" | "yes" | "Yes" => true,
-        _ => false
-    }
-}
-
-
-// Init command implementation
-fn init(args: &ArgMatches) -> Result<(), Box<Error>> {
-
-    let book_dir = get_book_dir(args);
-    let mut book = MDBook::new(&book_dir);
-
-    // Call the function that does the initialization
-    try!(book.init());
-
-    // If flag `--theme` is present, copy theme to src
-    if args.is_present("theme") {
-
-        // Skip this id `--force` is present
-        if !args.is_present("force") {
-            // Print warning
-            print!("\nCopying the default theme to {:?}", book.get_src());
-            println!("could potentially overwrite files already present in that directory.");
-            print!("\nAre you sure you want to continue? (y/n) ");
-
-            // Read answer from user and exit if it's not 'yes'
-            if !confirm() {
-                println!("\nSkipping...\n");
-                println!("All done, no errors...");
-                ::std::process::exit(0);
-            }
-        }
-
-        // Call the function that copies the theme
-        try!(book.copy_theme());
-        println!("\nTheme copied.");
-
-    }
-
-    println!("\nAll done, no errors...");
-
-    Ok(())
-}
-
-
-// Build command implementation
-fn build(args: &ArgMatches) -> Result<(), Box<Error>> {
-    let book_dir = get_book_dir(args);
-    let mut book = MDBook::new(&book_dir).read_config();
-
-    try!(book.build());
-
-    Ok(())
-}
-
-
-// Watch command implementation
-#[cfg(feature = "watch")]
-fn watch(args: &ArgMatches) -> Result<(), Box<Error>> {
-    let book_dir = get_book_dir(args);
-    let book = MDBook::new(&book_dir).read_config();
-
-    // Create a channel to receive the events.
-     let (tx, rx) = channel();
-
-     let w: Result<notify::RecommendedWatcher, notify::Error> = notify::Watcher::new(tx);
-
-     match w {
-         Ok(mut watcher) => {
-
-             // Add the source directory to the watcher
-             if let Err(e) = watcher.watch(book.get_src()) {
-                 println!("Error while watching {:?}:\n    {:?}", book.get_src(), e);
-                 ::std::process::exit(0);
-             };
-
-             // Add the book.json file to the watcher if it exists, because it's not
-             // located in the source directory
-             if let Err(_) = watcher.watch(book_dir.join("book.json")) {
-                 // do nothing if book.json is not found
-             }
-
-             let previous_time = time::get_time().sec;
-
-             crossbeam::scope(|scope| {
-                 loop {
-                     match rx.recv() {
-                         Ok(event) => {
-
-                             // Skip the event if an event has already been issued in the last second
-                             if time::get_time().sec - previous_time < 1 { continue }
-
-                             if let Some(path) = event.path {
-                                 // Trigger the build process in a new thread (to keep receiving events)
-                                 scope.spawn(move || {
-                                     println!("File changed: {:?}\nBuilding book...\n", path);
-                                     match build(args) {
-                                         Err(e) => println!("Error while building: {:?}", e),
-                                         _ => {}
-                                     }
-                                     println!("");
-                                 });
-
-                             } else {
-                                 continue;
-                             }
-                         },
-                         Err(e) => {
-                             println!("An error occured: {:?}", e);
-                         }
-                     }
-                 }
-             });
-
-         },
-         Err(e) => {
-             println!("Error while trying to watch the files:\n\n\t{:?}", e);
-             ::std::process::exit(0);
-         }
-     }
-
-     Ok(())
- }
-
-
-
-fn test(args: &ArgMatches) -> Result<(), Box<Error>> {
-    let book_dir = get_book_dir(args);
-    let mut book = MDBook::new(&book_dir).read_config();
-
-    try!(book.test());
-
-    Ok(())
-}
-
-
-
-fn get_book_dir(args: &ArgMatches) -> PathBuf {
-    if let Some(dir) = args.value_of("dir") {
-        // Check if path is relative from current dir, or absolute...
-        let p = Path::new(dir);
-        if p.is_relative() {
-           env::current_dir().unwrap().join(dir)
-        } else {
-           p.to_path_buf()
-        }
-    } else {
-        env::current_dir().unwrap()
-    }
-}

src/book/book.rs

@@ -0,0 +1,640 @@
+use std::collections::VecDeque;
+use std::fmt::{self, Display, Formatter};
+use std::fs::{self, File};
+use std::io::{Read, Write};
+use std::path::{Path, PathBuf};
+
+use super::summary::{parse_summary, Link, SectionNumber, Summary, SummaryItem};
+use crate::config::BuildConfig;
+use crate::errors::*;
+use crate::utils::bracket_escape;
+use log::debug;
+use serde::{Deserialize, Serialize};
+
+/// Load a book into memory from its `src/` directory.
+pub fn load_book<P: AsRef<Path>>(src_dir: P, cfg: &BuildConfig) -> Result<Book> {
+    let src_dir = src_dir.as_ref();
+    let summary_md = src_dir.join("SUMMARY.md");
+
+    let mut summary_content = String::new();
+    File::open(&summary_md)
+        .with_context(|| format!("Couldn't open SUMMARY.md in {:?} directory", src_dir))?
+        .read_to_string(&mut summary_content)?;
+
+    let summary = parse_summary(&summary_content)
+        .with_context(|| format!("Summary parsing failed for file={:?}", summary_md))?;
+
+    if cfg.create_missing {
+        create_missing(src_dir, &summary).with_context(|| "Unable to create missing chapters")?;
+    }
+
+    load_book_from_disk(&summary, src_dir)
+}
+
+fn create_missing(src_dir: &Path, summary: &Summary) -> Result<()> {
+    let mut items: Vec<_> = summary
+        .prefix_chapters
+        .iter()
+        .chain(summary.numbered_chapters.iter())
+        .chain(summary.suffix_chapters.iter())
+        .collect();
+
+    while !items.is_empty() {
+        let next = items.pop().expect("already checked");
+
+        if let SummaryItem::Link(ref link) = *next {
+            if let Some(ref location) = link.location {
+                let filename = src_dir.join(location);
+                if !filename.exists() {
+                    if let Some(parent) = filename.parent() {
+                        if !parent.exists() {
+                            fs::create_dir_all(parent)?;
+                        }
+                    }
+                    debug!("Creating missing file {}", filename.display());
+
+                    let mut f = File::create(&filename).with_context(|| {
+                        format!("Unable to create missing file: {}", filename.display())
+                    })?;
+                    writeln!(f, "# {}", bracket_escape(&link.name))?;
+                }
+            }
+
+            items.extend(&link.nested_items);
+        }
+    }
+
+    Ok(())
+}
+
+/// A dumb tree structure representing a book.
+///
+/// For the moment a book is just a collection of [`BookItems`] which are
+/// accessible by either iterating (immutably) over the book with [`iter()`], or
+/// recursively applying a closure to each section to mutate the chapters, using
+/// [`for_each_mut()`].
+///
+/// [`iter()`]: #method.iter
+/// [`for_each_mut()`]: #method.for_each_mut
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
+pub struct Book {
+    /// The sections in this book.
+    pub sections: Vec<BookItem>,
+    __non_exhaustive: (),
+}
+
+impl Book {
+    /// Create an empty book.
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    /// Get a depth-first iterator over the items in the book.
+    pub fn iter(&self) -> BookItems<'_> {
+        BookItems {
+            items: self.sections.iter().collect(),
+        }
+    }
+
+    /// Recursively apply a closure to each item in the book, allowing you to
+    /// mutate them.
+    ///
+    /// # Note
+    ///
+    /// Unlike the `iter()` method, this requires a closure instead of returning
+    /// an iterator. This is because using iterators can possibly allow you
+    /// to have iterator invalidation errors.
+    pub fn for_each_mut<F>(&mut self, mut func: F)
+    where
+        F: FnMut(&mut BookItem),
+    {
+        for_each_mut(&mut func, &mut self.sections);
+    }
+
+    /// Append a `BookItem` to the `Book`.
+    pub fn push_item<I: Into<BookItem>>(&mut self, item: I) -> &mut Self {
+        self.sections.push(item.into());
+        self
+    }
+}
+
+pub fn for_each_mut<'a, F, I>(func: &mut F, items: I)
+where
+    F: FnMut(&mut BookItem),
+    I: IntoIterator<Item = &'a mut BookItem>,
+{
+    for item in items {
+        if let BookItem::Chapter(ch) = item {
+            for_each_mut(func, &mut ch.sub_items);
+        }
+
+        func(item);
+    }
+}
+
+/// Enum representing any type of item which can be added to a book.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum BookItem {
+    /// A nested chapter.
+    Chapter(Chapter),
+    /// A section separator.
+    Separator,
+    /// A part title.
+    PartTitle(String),
+}
+
+impl From<Chapter> for BookItem {
+    fn from(other: Chapter) -> BookItem {
+        BookItem::Chapter(other)
+    }
+}
+
+/// The representation of a "chapter", usually mapping to a single file on
+/// disk however it may contain multiple sub-chapters.
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
+pub struct Chapter {
+    /// The chapter's name.
+    pub name: String,
+    /// The chapter's contents.
+    pub content: String,
+    /// The chapter's section number, if it has one.
+    pub number: Option<SectionNumber>,
+    /// Nested items.
+    pub sub_items: Vec<BookItem>,
+    /// The chapter's location, relative to the `SUMMARY.md` file.
+    pub path: Option<PathBuf>,
+    /// The chapter's source file, relative to the `SUMMARY.md` file.
+    pub source_path: Option<PathBuf>,
+    /// An ordered list of the names of each chapter above this one in the hierarchy.
+    pub parent_names: Vec<String>,
+}
+
+impl Chapter {
+    /// Create a new chapter with the provided content.
+    pub fn new<P: Into<PathBuf>>(
+        name: &str,
+        content: String,
+        p: P,
+        parent_names: Vec<String>,
+    ) -> Chapter {
+        let path: PathBuf = p.into();
+        Chapter {
+            name: name.to_string(),
+            content,
+            path: Some(path.clone()),
+            source_path: Some(path),
+            parent_names,
+            ..Default::default()
+        }
+    }
+
+    /// Create a new draft chapter that is not attached to a source markdown file (and thus
+    /// has no content).
+    pub fn new_draft(name: &str, parent_names: Vec<String>) -> Self {
+        Chapter {
+            name: name.to_string(),
+            content: String::new(),
+            path: None,
+            source_path: None,
+            parent_names,
+            ..Default::default()
+        }
+    }
+
+    /// Check if the chapter is a draft chapter, meaning it has no path to a source markdown file.
+    pub fn is_draft_chapter(&self) -> bool {
+        self.path.is_none()
+    }
+}
+
+/// Use the provided `Summary` to load a `Book` from disk.
+///
+/// You need to pass in the book's source directory because all the links in
+/// `SUMMARY.md` give the chapter locations relative to it.
+pub(crate) fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P) -> Result<Book> {
+    debug!("Loading the book from disk");
+    let src_dir = src_dir.as_ref();
+
+    let prefix = summary.prefix_chapters.iter();
+    let numbered = summary.numbered_chapters.iter();
+    let suffix = summary.suffix_chapters.iter();
+
+    let summary_items = prefix.chain(numbered).chain(suffix);
+
+    let mut chapters = Vec::new();
+
+    for summary_item in summary_items {
+        let chapter = load_summary_item(summary_item, src_dir, Vec::new())?;
+        chapters.push(chapter);
+    }
+
+    Ok(Book {
+        sections: chapters,
+        __non_exhaustive: (),
+    })
+}
+
+fn load_summary_item<P: AsRef<Path> + Clone>(
+    item: &SummaryItem,
+    src_dir: P,
+    parent_names: Vec<String>,
+) -> Result<BookItem> {
+    match item {
+        SummaryItem::Separator => Ok(BookItem::Separator),
+        SummaryItem::Link(ref link) => {
+            load_chapter(link, src_dir, parent_names).map(BookItem::Chapter)
+        }
+        SummaryItem::PartTitle(title) => Ok(BookItem::PartTitle(title.clone())),
+    }
+}
+
+fn load_chapter<P: AsRef<Path>>(
+    link: &Link,
+    src_dir: P,
+    parent_names: Vec<String>,
+) -> Result<Chapter> {
+    let src_dir = src_dir.as_ref();
+
+    let mut ch = if let Some(ref link_location) = link.location {
+        debug!("Loading {} ({})", link.name, link_location.display());
+
+        let location = if link_location.is_absolute() {
+            link_location.clone()
+        } else {
+            src_dir.join(link_location)
+        };
+
+        let mut f = File::open(&location)
+            .with_context(|| format!("Chapter file not found, {}", link_location.display()))?;
+
+        let mut content = String::new();
+        f.read_to_string(&mut content).with_context(|| {
+            format!("Unable to read \"{}\" ({})", link.name, location.display())
+        })?;
+
+        if content.as_bytes().starts_with(b"\xef\xbb\xbf") {
+            content.replace_range(..3, "");
+        }
+
+        let stripped = location
+            .strip_prefix(&src_dir)
+            .expect("Chapters are always inside a book");
+
+        Chapter::new(&link.name, content, stripped, parent_names.clone())
+    } else {
+        Chapter::new_draft(&link.name, parent_names.clone())
+    };
+
+    let mut sub_item_parents = parent_names;
+
+    ch.number = link.number.clone();
+
+    sub_item_parents.push(link.name.clone());
+    let sub_items = link
+        .nested_items
+        .iter()
+        .map(|i| load_summary_item(i, src_dir, sub_item_parents.clone()))
+        .collect::<Result<Vec<_>>>()?;
+
+    ch.sub_items = sub_items;
+
+    Ok(ch)
+}
+
+/// A depth-first iterator over the items in a book.
+///
+/// # Note
+///
+/// This struct shouldn't be created directly, instead prefer the
+/// [`Book::iter()`] method.
+pub struct BookItems<'a> {
+    items: VecDeque<&'a BookItem>,
+}
+
+impl<'a> Iterator for BookItems<'a> {
+    type Item = &'a BookItem;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let item = self.items.pop_front();
+
+        if let Some(&BookItem::Chapter(ref ch)) = item {
+            // if we wanted a breadth-first iterator we'd `extend()` here
+            for sub_item in ch.sub_items.iter().rev() {
+                self.items.push_front(sub_item);
+            }
+        }
+
+        item
+    }
+}
+
+impl Display for Chapter {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        if let Some(ref section_number) = self.number {
+            write!(f, "{} ", section_number)?;
+        }
+
+        write!(f, "{}", self.name)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::Write;
+    use tempfile::{Builder as TempFileBuilder, TempDir};
+
+    const DUMMY_SRC: &str = "
+# Dummy Chapter
+
+this is some dummy text.
+
+And here is some \
+                                     more text.
+";
+
+    /// Create a dummy `Link` in a temporary directory.
+    fn dummy_link() -> (Link, TempDir) {
+        let temp = TempFileBuilder::new().prefix("book").tempdir().unwrap();
+
+        let chapter_path = temp.path().join("chapter_1.md");
+        File::create(&chapter_path)
+            .unwrap()
+            .write_all(DUMMY_SRC.as_bytes())
+            .unwrap();
+
+        let link = Link::new("Chapter 1", chapter_path);
+
+        (link, temp)
+    }
+
+    /// Create a nested `Link` written to a temporary directory.
+    fn nested_links() -> (Link, TempDir) {
+        let (mut root, temp_dir) = dummy_link();
+
+        let second_path = temp_dir.path().join("second.md");
+
+        File::create(&second_path)
+            .unwrap()
+            .write_all(b"Hello World!")
+            .unwrap();
+
+        let mut second = Link::new("Nested Chapter 1", &second_path);
+        second.number = Some(SectionNumber(vec![1, 2]));
+
+        root.nested_items.push(second.clone().into());
+        root.nested_items.push(SummaryItem::Separator);
+        root.nested_items.push(second.into());
+
+        (root, temp_dir)
+    }
+
+    #[test]
+    fn load_a_single_chapter_from_disk() {
+        let (link, temp_dir) = dummy_link();
+        let should_be = Chapter::new(
+            "Chapter 1",
+            DUMMY_SRC.to_string(),
+            "chapter_1.md",
+            Vec::new(),
+        );
+
+        let got = load_chapter(&link, temp_dir.path(), Vec::new()).unwrap();
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn load_a_single_chapter_with_utf8_bom_from_disk() {
+        let temp_dir = TempFileBuilder::new().prefix("book").tempdir().unwrap();
+
+        let chapter_path = temp_dir.path().join("chapter_1.md");
+        File::create(&chapter_path)
+            .unwrap()
+            .write_all(("\u{feff}".to_owned() + DUMMY_SRC).as_bytes())
+            .unwrap();
+
+        let link = Link::new("Chapter 1", chapter_path);
+
+        let should_be = Chapter::new(
+            "Chapter 1",
+            DUMMY_SRC.to_string(),
+            "chapter_1.md",
+            Vec::new(),
+        );
+
+        let got = load_chapter(&link, temp_dir.path(), Vec::new()).unwrap();
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn cant_load_a_nonexistent_chapter() {
+        let link = Link::new("Chapter 1", "/foo/bar/baz.md");
+
+        let got = load_chapter(&link, "", Vec::new());
+        assert!(got.is_err());
+    }
+
+    #[test]
+    fn load_recursive_link_with_separators() {
+        let (root, temp) = nested_links();
+
+        let nested = Chapter {
+            name: String::from("Nested Chapter 1"),
+            content: String::from("Hello World!"),
+            number: Some(SectionNumber(vec![1, 2])),
+            path: Some(PathBuf::from("second.md")),
+            source_path: Some(PathBuf::from("second.md")),
+            parent_names: vec![String::from("Chapter 1")],
+            sub_items: Vec::new(),
+        };
+        let should_be = BookItem::Chapter(Chapter {
+            name: String::from("Chapter 1"),
+            content: String::from(DUMMY_SRC),
+            number: None,
+            path: Some(PathBuf::from("chapter_1.md")),
+            source_path: Some(PathBuf::from("chapter_1.md")),
+            parent_names: Vec::new(),
+            sub_items: vec![
+                BookItem::Chapter(nested.clone()),
+                BookItem::Separator,
+                BookItem::Chapter(nested),
+            ],
+        });
+
+        let got = load_summary_item(&SummaryItem::Link(root), temp.path(), Vec::new()).unwrap();
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn load_a_book_with_a_single_chapter() {
+        let (link, temp) = dummy_link();
+        let summary = Summary {
+            numbered_chapters: vec![SummaryItem::Link(link)],
+            ..Default::default()
+        };
+        let should_be = Book {
+            sections: vec![BookItem::Chapter(Chapter {
+                name: String::from("Chapter 1"),
+                content: String::from(DUMMY_SRC),
+                path: Some(PathBuf::from("chapter_1.md")),
+                source_path: Some(PathBuf::from("chapter_1.md")),
+                ..Default::default()
+            })],
+            ..Default::default()
+        };
+
+        let got = load_book_from_disk(&summary, temp.path()).unwrap();
+
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn book_iter_iterates_over_sequential_items() {
+        let book = Book {
+            sections: vec![
+                BookItem::Chapter(Chapter {
+                    name: String::from("Chapter 1"),
+                    content: String::from(DUMMY_SRC),
+                    ..Default::default()
+                }),
+                BookItem::Separator,
+            ],
+            ..Default::default()
+        };
+
+        let should_be: Vec<_> = book.sections.iter().collect();
+
+        let got: Vec<_> = book.iter().collect();
+
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn iterate_over_nested_book_items() {
+        let book = Book {
+            sections: vec![
+                BookItem::Chapter(Chapter {
+                    name: String::from("Chapter 1"),
+                    content: String::from(DUMMY_SRC),
+                    number: None,
+                    path: Some(PathBuf::from("Chapter_1/index.md")),
+                    source_path: Some(PathBuf::from("Chapter_1/index.md")),
+                    parent_names: Vec::new(),
+                    sub_items: vec![
+                        BookItem::Chapter(Chapter::new(
+                            "Hello World",
+                            String::new(),
+                            "Chapter_1/hello.md",
+                            Vec::new(),
+                        )),
+                        BookItem::Separator,
+                        BookItem::Chapter(Chapter::new(
+                            "Goodbye World",
+                            String::new(),
+                            "Chapter_1/goodbye.md",
+                            Vec::new(),
+                        )),
+                    ],
+                }),
+                BookItem::Separator,
+            ],
+            ..Default::default()
+        };
+
+        let got: Vec<_> = book.iter().collect();
+
+        assert_eq!(got.len(), 5);
+
+        // checking the chapter names are in the order should be sufficient here...
+        let chapter_names: Vec<String> = got
+            .into_iter()
+            .filter_map(|i| match *i {
+                BookItem::Chapter(ref ch) => Some(ch.name.clone()),
+                _ => None,
+            })
+            .collect();
+        let should_be: Vec<_> = vec![
+            String::from("Chapter 1"),
+            String::from("Hello World"),
+            String::from("Goodbye World"),
+        ];
+
+        assert_eq!(chapter_names, should_be);
+    }
+
+    #[test]
+    fn for_each_mut_visits_all_items() {
+        let mut book = Book {
+            sections: vec![
+                BookItem::Chapter(Chapter {
+                    name: String::from("Chapter 1"),
+                    content: String::from(DUMMY_SRC),
+                    number: None,
+                    path: Some(PathBuf::from("Chapter_1/index.md")),
+                    source_path: Some(PathBuf::from("Chapter_1/index.md")),
+                    parent_names: Vec::new(),
+                    sub_items: vec![
+                        BookItem::Chapter(Chapter::new(
+                            "Hello World",
+                            String::new(),
+                            "Chapter_1/hello.md",
+                            Vec::new(),
+                        )),
+                        BookItem::Separator,
+                        BookItem::Chapter(Chapter::new(
+                            "Goodbye World",
+                            String::new(),
+                            "Chapter_1/goodbye.md",
+                            Vec::new(),
+                        )),
+                    ],
+                }),
+                BookItem::Separator,
+            ],
+            ..Default::default()
+        };
+
+        let num_items = book.iter().count();
+        let mut visited = 0;
+
+        book.for_each_mut(|_| visited += 1);
+
+        assert_eq!(visited, num_items);
+    }
+
+    #[test]
+    fn cant_load_chapters_with_an_empty_path() {
+        let (_, temp) = dummy_link();
+        let summary = Summary {
+            numbered_chapters: vec![SummaryItem::Link(Link {
+                name: String::from("Empty"),
+                location: Some(PathBuf::from("")),
+                ..Default::default()
+            })],
+
+            ..Default::default()
+        };
+
+        let got = load_book_from_disk(&summary, temp.path());
+        assert!(got.is_err());
+    }
+
+    #[test]
+    fn cant_load_chapters_when_the_link_is_a_directory() {
+        let (_, temp) = dummy_link();
+        let dir = temp.path().join("nested");
+        fs::create_dir(&dir).unwrap();
+
+        let summary = Summary {
+            numbered_chapters: vec![SummaryItem::Link(Link {
+                name: String::from("nested"),
+                location: Some(dir),
+                ..Default::default()
+            })],
+            ..Default::default()
+        };
+
+        let got = load_book_from_disk(&summary, temp.path());
+        assert!(got.is_err());
+    }
+}

src/book/bookconfig.rs

@@ -1,106 +0,0 @@
-extern crate rustc_serialize;
-use self::rustc_serialize::json::Json;
-use std::fs::File;
-use std::io::Read;
-use std::path::{Path, PathBuf};
-
-#[derive(Debug, Clone)]
-pub struct BookConfig {
-    pub title: String,
-    pub author: String,
-    root: PathBuf,
-    dest: PathBuf,
-    src: PathBuf,
-    pub indent_spaces: i32,
-    multilingual: bool,
-}
-
-
-impl BookConfig {
-    pub fn new(root: &Path) -> Self {
-        BookConfig {
-            title: String::new(),
-            author: String::new(),
-            root: root.to_owned(),
-            dest: PathBuf::from("book"),
-            src: PathBuf::from("src"),
-            indent_spaces: 4,               // indentation used for SUMMARY.md
-            multilingual: false,
-        }
-    }
-
-    pub fn read_config(&mut self, root: &Path) -> &mut Self {
-
-        debug!("[fn]: read_config");
-
-        // If the file does not exist, return early
-        let mut config_file = match File::open(root.join("book.json")) {
-            Ok(f) => f,
-            Err(_) => {
-                debug!("[*]: Failed to open {:?}", root.join("book.json"));
-                return self
-            },
-        };
-
-        debug!("[*]: Reading config");
-        let mut data = String::new();
-
-        // Just return if an error occured.
-        // I would like to propagate the error, but I have to return `&self`
-        if let Err(_) = config_file.read_to_string(&mut data) { return self }
-
-        // Convert to JSON
-        if let Ok(config) = Json::from_str(&data) {
-            // Extract data
-
-            debug!("[*]: Extracting data from config");
-            // Title & author
-            if let Some(a) = config.find_path(&["title"]) { self.title = a.to_string().replace("\"", "") }
-            if let Some(a) = config.find_path(&["author"]) { self.author = a.to_string().replace("\"", "") }
-
-            // Destination
-            if let Some(a) = config.find_path(&["dest"]) {
-                let dest = PathBuf::from(&a.to_string().replace("\"", ""));
-
-                // If path is relative make it absolute from the parent directory of src
-                match dest.is_relative() {
-                    true => {
-                        let dest = self.get_root().join(&dest).to_owned();
-                        self.set_dest(&dest);
-                    },
-                    false => { self.set_dest(&dest); },
-                }
-            }
-        }
-
-        self
-    }
-
-    pub fn get_root(&self) -> &Path {
-        &self.root
-    }
-
-    pub fn set_root(&mut self, root: &Path) -> &mut Self {
-        self.root = root.to_owned();
-        self
-    }
-
-    pub fn get_dest(&self) -> &Path {
-        &self.dest
-    }
-
-    pub fn set_dest(&mut self, dest: &Path) -> &mut Self {
-        self.dest = dest.to_owned();
-        self
-    }
-
-    pub fn get_src(&self) -> &Path {
-        &self.src
-    }
-
-    pub fn set_src(&mut self, src: &Path) -> &mut Self {
-        self.src = src.to_owned();
-        self
-    }
-
-}

src/book/bookitem.rs

@@ -1,89 +0,0 @@
-extern crate rustc_serialize;
-
-use self::rustc_serialize::json::{Json, ToJson};
-use std::path::PathBuf;
-use std::collections::BTreeMap;
-
-#[derive(Debug, Clone)]
-pub enum BookItem {
-    Chapter(String, Chapter), // String = section
-    Affix(Chapter),
-    Spacer,
-}
-
-#[derive(Debug, Clone)]
-pub struct Chapter {
-    pub name: String,
-    pub path: PathBuf,
-    pub sub_items: Vec<BookItem>,
-}
-
-#[derive(Debug, Clone)]
-pub struct BookItems<'a> {
-    pub items: &'a [BookItem],
-    pub current_index: usize,
-    pub stack: Vec<(&'a [BookItem], usize)>,
-}
-
-
-impl Chapter {
-
-    pub fn new(name: String, path: PathBuf) -> Self {
-
-        Chapter {
-            name: name,
-            path: path,
-            sub_items: vec![],
-        }
-    }
-}
-
-
-impl ToJson for Chapter {
-
-    fn to_json(&self) -> Json {
-        let mut m: BTreeMap<String, Json> = BTreeMap::new();
-        m.insert("name".to_owned(), self.name.to_json());
-        m.insert("path".to_owned(),self.path.to_str()
-            .expect("Json conversion failed for path").to_json()
-        );
-        m.to_json()
-    }
-}
-
-
-
-// Shamelessly copied from Rustbook
-// (https://github.com/rust-lang/rust/blob/master/src/rustbook/book.rs)
-impl<'a> Iterator for BookItems<'a> {
-    type Item = &'a BookItem;
-
-    fn next(&mut self) -> Option<&'a BookItem> {
-        loop {
-            if self.current_index >= self.items.len() {
-                match self.stack.pop() {
-                    None => return None,
-                    Some((parent_items, parent_idx)) => {
-                        self.items = parent_items;
-                        self.current_index = parent_idx + 1;
-                    }
-                }
-            } else {
-                let cur = self.items.get(self.current_index).unwrap();
-
-                match *cur {
-                    BookItem::Chapter(_, ref ch) | BookItem::Affix(ref ch) => {
-                        self.stack.push((self.items, self.current_index));
-                        self.items = &ch.sub_items[..];
-                        self.current_index = 0;
-                    },
-                    BookItem::Spacer => {
-                        self.current_index += 1;
-                    }
-                }
-
-                return Some(cur)
-            }
-        }
-    }
-}

src/book/init.rs

@@ -0,0 +1,224 @@
+use std::fs::{self, File};
+use std::io::Write;
+use std::path::PathBuf;
+
+use super::MDBook;
+use crate::config::Config;
+use crate::errors::*;
+use crate::theme;
+use crate::utils::fs::write_file;
+use log::{debug, error, info, trace};
+
+/// A helper for setting up a new book and its directory structure.
+#[derive(Debug, Clone, PartialEq)]
+pub struct BookBuilder {
+    root: PathBuf,
+    create_gitignore: bool,
+    config: Config,
+    copy_theme: bool,
+}
+
+impl BookBuilder {
+    /// Create a new `BookBuilder` which will generate a book in the provided
+    /// root directory.
+    pub fn new<P: Into<PathBuf>>(root: P) -> BookBuilder {
+        BookBuilder {
+            root: root.into(),
+            create_gitignore: false,
+            config: Config::default(),
+            copy_theme: false,
+        }
+    }
+
+    /// Set the [`Config`] to be used.
+    pub fn with_config(&mut self, cfg: Config) -> &mut BookBuilder {
+        self.config = cfg;
+        self
+    }
+
+    /// Get the config used by the `BookBuilder`.
+    pub fn config(&self) -> &Config {
+        &self.config
+    }
+
+    /// Should the theme be copied into the generated book (so users can tweak
+    /// it)?
+    pub fn copy_theme(&mut self, copy: bool) -> &mut BookBuilder {
+        self.copy_theme = copy;
+        self
+    }
+
+    /// Should we create a `.gitignore` file?
+    pub fn create_gitignore(&mut self, create: bool) -> &mut BookBuilder {
+        self.create_gitignore = create;
+        self
+    }
+
+    /// Generate the actual book. This will:
+    ///
+    /// - Create the directory structure.
+    /// - Stub out some dummy chapters and the `SUMMARY.md`.
+    /// - Create a `.gitignore` (if applicable)
+    /// - Create a themes directory and populate it (if applicable)
+    /// - Generate a `book.toml` file,
+    /// - Then load the book so we can build it or run tests.
+    pub fn build(&self) -> Result<MDBook> {
+        info!("Creating a new book with stub content");
+
+        self.create_directory_structure()
+            .with_context(|| "Unable to create directory structure")?;
+
+        self.create_stub_files()
+            .with_context(|| "Unable to create stub files")?;
+
+        if self.create_gitignore {
+            self.build_gitignore()
+                .with_context(|| "Unable to create .gitignore")?;
+        }
+
+        if self.copy_theme {
+            self.copy_across_theme()
+                .with_context(|| "Unable to copy across the theme")?;
+        }
+
+        self.write_book_toml()?;
+
+        match MDBook::load(&self.root) {
+            Ok(book) => Ok(book),
+            Err(e) => {
+                error!("{}", e);
+
+                panic!(
+                    "The BookBuilder should always create a valid book. If you are seeing this it \
+                     is a bug and should be reported."
+                );
+            }
+        }
+    }
+
+    fn write_book_toml(&self) -> Result<()> {
+        debug!("Writing book.toml");
+        let book_toml = self.root.join("book.toml");
+        let cfg = toml::to_string(&self.config)
+            .with_context(|| "Unable to serialize the config")?
+            .into_bytes();
+
+        File::create(book_toml)
+            .with_context(|| "Couldn't create book.toml")?
+            .write_all(&cfg)
+            .with_context(|| "Unable to write config to book.toml")?;
+        Ok(())
+    }
+
+    fn copy_across_theme(&self) -> Result<()> {
+        debug!("Copying theme");
+
+        let html_config = self.config.html_config().unwrap_or_default();
+        let themedir = html_config.theme_dir(&self.root);
+
+        if !themedir.exists() {
+            debug!(
+                "{} does not exist, creating the directory",
+                themedir.display()
+            );
+            fs::create_dir(&themedir)?;
+        }
+
+        let mut index = File::create(themedir.join("index.hbs"))?;
+        index.write_all(theme::INDEX)?;
+
+        let cssdir = themedir.join("css");
+        if !cssdir.exists() {
+            fs::create_dir(&cssdir)?;
+        }
+
+        let mut general_css = File::create(cssdir.join("general.css"))?;
+        general_css.write_all(theme::GENERAL_CSS)?;
+
+        let mut chrome_css = File::create(cssdir.join("chrome.css"))?;
+        chrome_css.write_all(theme::CHROME_CSS)?;
+
+        if html_config.print.enable {
+            let mut print_css = File::create(cssdir.join("print.css"))?;
+            print_css.write_all(theme::PRINT_CSS)?;
+        }
+
+        let mut variables_css = File::create(cssdir.join("variables.css"))?;
+        variables_css.write_all(theme::VARIABLES_CSS)?;
+
+        let mut favicon = File::create(themedir.join("favicon.png"))?;
+        favicon.write_all(theme::FAVICON_PNG)?;
+
+        let mut favicon = File::create(themedir.join("favicon.svg"))?;
+        favicon.write_all(theme::FAVICON_SVG)?;
+
+        let mut js = File::create(themedir.join("book.js"))?;
+        js.write_all(theme::JS)?;
+
+        let mut highlight_css = File::create(themedir.join("highlight.css"))?;
+        highlight_css.write_all(theme::HIGHLIGHT_CSS)?;
+
+        let mut highlight_js = File::create(themedir.join("highlight.js"))?;
+        highlight_js.write_all(theme::HIGHLIGHT_JS)?;
+
+        write_file(&themedir.join("fonts"), "fonts.css", theme::fonts::CSS)?;
+        for (file_name, contents) in theme::fonts::LICENSES {
+            write_file(&themedir, file_name, contents)?;
+        }
+        for (file_name, contents) in theme::fonts::OPEN_SANS.iter() {
+            write_file(&themedir, file_name, contents)?;
+        }
+        write_file(
+            &themedir,
+            theme::fonts::SOURCE_CODE_PRO.0,
+            theme::fonts::SOURCE_CODE_PRO.1,
+        )?;
+
+        Ok(())
+    }
+
+    fn build_gitignore(&self) -> Result<()> {
+        debug!("Creating .gitignore");
+
+        let mut f = File::create(self.root.join(".gitignore"))?;
+
+        writeln!(f, "{}", self.config.build.build_dir.display())?;
+
+        Ok(())
+    }
+
+    fn create_stub_files(&self) -> Result<()> {
+        debug!("Creating example book contents");
+        let src_dir = self.root.join(&self.config.book.src);
+
+        let summary = src_dir.join("SUMMARY.md");
+        if !summary.exists() {
+            trace!("No summary found creating stub summary and chapter_1.md.");
+            let mut f = File::create(&summary).with_context(|| "Unable to create SUMMARY.md")?;
+            writeln!(f, "# Summary")?;
+            writeln!(f)?;
+            writeln!(f, "- [Chapter 1](./chapter_1.md)")?;
+
+            let chapter_1 = src_dir.join("chapter_1.md");
+            let mut f =
+                File::create(&chapter_1).with_context(|| "Unable to create chapter_1.md")?;
+            writeln!(f, "# Chapter 1")?;
+        } else {
+            trace!("Existing summary found, no need to create stub files.");
+        }
+        Ok(())
+    }
+
+    fn create_directory_structure(&self) -> Result<()> {
+        debug!("Creating directory tree");
+        fs::create_dir_all(&self.root)?;
+
+        let src = self.root.join(&self.config.book.src);
+        fs::create_dir_all(&src)?;
+
+        let build = self.root.join(&self.config.build.build_dir);
+        fs::create_dir_all(&build)?;
+
+        Ok(())
+    }
+}

src/book/mdbook.rs

@@ -1,357 +0,0 @@
-use std::path::{Path, PathBuf};
-use std::fs::{self, File};
-use std::error::Error;
-use std::io;
-use std::io::Write;
-use std::io::ErrorKind;
-use std::process::Command;
-
-use {BookConfig, BookItem, theme, parse, utils};
-use book::BookItems;
-use renderer::{Renderer, HtmlHandlebars};
-
-
-pub struct MDBook {
-    config: BookConfig,
-    pub content: Vec<BookItem>,
-    renderer: Box<Renderer>,
-}
-
-impl MDBook {
-
-    /// Create a new `MDBook` struct with root directory `root`
-    ///
-    /// - The default source directory is set to `root/src`
-    /// - The default output directory is set to `root/book`
-    ///
-    /// They can both be changed by using [`set_src()`](#method.set_src) and [`set_dest()`](#method.set_dest)
-
-    pub fn new(root: &Path) -> MDBook {
-
-        if !root.exists() || !root.is_dir() {
-            output!("{:?} No directory with that name", root);
-        }
-
-        MDBook {
-            content: vec![],
-            config: BookConfig::new(root)
-                        .set_src(&root.join("src"))
-                        .set_dest(&root.join("book"))
-                        .to_owned(),
-            renderer: Box::new(HtmlHandlebars::new()),
-        }
-    }
-
-    /// Returns a flat depth-first iterator over the elements of the book, it returns an [BookItem enum](bookitem.html):
-    /// `(section: String, bookitem: &BookItem)`
-    ///
-    /// ```no_run
-    /// # extern crate mdbook;
-    /// # use mdbook::MDBook;
-    /// # use mdbook::BookItem;
-    /// # use std::path::Path;
-    /// # fn main() {
-    /// # let mut book = MDBook::new(Path::new("mybook"));
-    /// for item in book.iter() {
-    ///     match item {
-    ///         &BookItem::Chapter(ref section, ref chapter) => {},
-    ///         &BookItem::Affix(ref chapter) => {},
-    ///         &BookItem::Spacer => {},
-    ///     }
-    /// }
-    ///
-    /// // would print something like this:
-    /// // 1. Chapter 1
-    /// // 1.1 Sub Chapter
-    /// // 1.2 Sub Chapter
-    /// // 2. Chapter 2
-    /// //
-    /// // etc.
-    /// # }
-    /// ```
-
-    pub fn iter(&self) -> BookItems {
-        BookItems {
-            items: &self.content[..],
-            current_index: 0,
-            stack: Vec::new(),
-        }
-    }
-
-    /// `init()` creates some boilerplate files and directories to get you started with your book.
-    ///
-    /// ```text
-    /// book-test/
-    /// ├── book
-    /// └── src
-    ///     ├── chapter_1.md
-    ///     └── SUMMARY.md
-    /// ```
-    ///
-    /// It uses the paths given as source and output directories and adds a `SUMMARY.md` and a
-    /// `chapter_1.md` to the source directory.
-
-    pub fn init(&mut self) -> Result<(), Box<Error>> {
-
-        debug!("[fn]: init");
-
-        if !self.config.get_root().exists() {
-            fs::create_dir_all(self.config.get_root()).unwrap();
-            output!("{:?} created", self.config.get_root());
-        }
-
-        {
-            let dest = self.config.get_dest();
-            let src = self.config.get_src();
-
-            if !dest.exists() {
-                debug!("[*]: {:?} does not exist, trying to create directory", dest);
-                try!(fs::create_dir(&dest));
-            }
-
-            if !src.exists() {
-                debug!("[*]: {:?} does not exist, trying to create directory", src);
-                try!(fs::create_dir(&src));
-            }
-
-            let summary = src.join("SUMMARY.md");
-
-            if !summary.exists() {
-
-                // Summary does not exist, create it
-
-                debug!("[*]: {:?} does not exist, trying to create SUMMARY.md", src.join("SUMMARY.md"));
-                let mut f = try!(File::create(&src.join("SUMMARY.md")));
-
-                debug!("[*]: Writing to SUMMARY.md");
-
-                try!(writeln!(f, "# Summary"));
-                try!(writeln!(f, ""));
-                try!(writeln!(f, "- [Chapter 1](./chapter_1.md)"));
-            }
-        }
-
-        // parse SUMMARY.md, and create the missing item related file
-        try!(self.parse_summary());
-
-        debug!("[*]: constructing paths for missing files");
-        for item in self.iter() {
-            debug!("[*]: item: {:?}", item);
-            match *item {
-                BookItem::Spacer => continue,
-                BookItem::Chapter(_, ref ch) | BookItem::Affix(ref ch) => {
-                    if ch.path != PathBuf::new() {
-                        let path = self.config.get_src().join(&ch.path);
-
-                        if !path.exists() {
-                            debug!("[*]: {:?} does not exist, trying to create file", path);
-                            try!(::std::fs::create_dir_all(path.parent().unwrap()));
-                            let mut f = try!(File::create(path));
-
-                            //debug!("[*]: Writing to {:?}", path);
-                            try!(writeln!(f, "# {}", ch.name));
-                        }
-                    }
-                }
-            }
-        }
-
-        debug!("[*]: init done");
-        Ok(())
-    }
-
-    /// The `build()` method is the one where everything happens. First it parses `SUMMARY.md` to
-    /// construct the book's structure in the form of a `Vec<BookItem>` and then calls `render()`
-    /// method of the current renderer.
-    ///
-    /// It is the renderer who generates all the output files.
-
-    pub fn build(&mut self) -> Result<(), Box<Error>> {
-        debug!("[fn]: build");
-
-        try!(self.init());
-
-        // Clean output directory
-        try!(utils::remove_dir_content(&self.config.get_dest()));
-
-        try!(self.renderer.render(&self));
-
-        Ok(())
-    }
-
-
-    pub fn copy_theme(&self) -> Result<(), Box<Error>> {
-        debug!("[fn]: copy_theme");
-
-        let theme_dir = self.config.get_src().join("theme");
-
-        if !theme_dir.exists() {
-            debug!("[*]: {:?} does not exist, trying to create directory", theme_dir);
-            try!(fs::create_dir(&theme_dir));
-        }
-
-        // index.hbs
-        let mut index = try!(File::create(&theme_dir.join("index.hbs")));
-        try!(index.write_all(theme::INDEX));
-
-        // book.css
-        let mut css = try!(File::create(&theme_dir.join("book.css")));
-        try!(css.write_all(theme::CSS));
-
-        // book.js
-        let mut js = try!(File::create(&theme_dir.join("book.js")));
-        try!(js.write_all(theme::JS));
-
-        // highlight.css
-        let mut highlight_css = try!(File::create(&theme_dir.join("highlight.css")));
-        try!(highlight_css.write_all(theme::HIGHLIGHT_CSS));
-
-        // highlight.js
-        let mut highlight_js = try!(File::create(&theme_dir.join("highlight.js")));
-        try!(highlight_js.write_all(theme::HIGHLIGHT_JS));
-
-        Ok(())
-    }
-
-    /// Parses the `book.json` file (if it exists) to extract the configuration parameters.
-    /// The `book.json` file should be in the root directory of the book.
-    /// The root directory is the one specified when creating a new `MDBook`
-    ///
-    /// ```no_run
-    /// # extern crate mdbook;
-    /// # use mdbook::MDBook;
-    /// # use std::path::Path;
-    /// # fn main() {
-    /// let mut book = MDBook::new(Path::new("root_dir"));
-    /// # }
-    /// ```
-    ///
-    /// In this example, `root_dir` will be the root directory of our book and is specified in function
-    /// of the current working directory by using a relative path instead of an absolute path.
-
-    pub fn read_config(mut self) -> Self {
-        let root = self.config.get_root().to_owned();
-        self.config.read_config(&root);
-        self
-    }
-
-    /// You can change the default renderer to another one by using this method. The only requirement
-    /// is for your renderer to implement the [Renderer trait](../../renderer/renderer/trait.Renderer.html)
-    ///
-    /// ```no_run
-    /// extern crate mdbook;
-    /// use mdbook::MDBook;
-    /// use mdbook::renderer::HtmlHandlebars;
-    /// # use std::path::Path;
-    ///
-    /// fn main() {
-    ///     let mut book = MDBook::new(Path::new("mybook"))
-    ///                         .set_renderer(Box::new(HtmlHandlebars::new()));
-    ///
-    ///     // In this example we replace the default renderer by the default renderer...
-    ///     // Don't forget to put your renderer in a Box
-    /// }
-    /// ```
-    ///
-    /// **note:** Don't forget to put your renderer in a `Box` before passing it to `set_renderer()`
-
-    pub fn set_renderer(mut self, renderer: Box<Renderer>) -> Self {
-        self.renderer = renderer;
-        self
-    }
-
-    pub fn test(&mut self) -> Result<(), Box<Error>> {
-        // read in the chapters
-        try!(self.parse_summary());
-        for item in self.iter() {
-
-            match *item {
-                BookItem::Chapter(_, ref ch) => {
-                    if ch.path != PathBuf::new() {
-
-                        let path = self.get_src().join(&ch.path);
-
-                        println!("[*]: Testing file: {:?}", path);
-
-                        let output_result = Command::new("rustdoc")
-                            .arg(&path)
-                            .arg("--test")
-                            .output();
-                        let output = try!(output_result);
-
-                        if !output.status.success() {
-                            return Err(Box::new(io::Error::new(ErrorKind::Other, format!(
-                                            "{}\n{}",
-                                            String::from_utf8_lossy(&output.stdout),
-                                            String::from_utf8_lossy(&output.stderr)))) as Box<Error>);
-                        }
-                    }
-                }
-                _ => {}
-            }
-        }
-        Ok(())
-    }
-
-    pub fn set_dest(mut self, dest: &Path) -> Self {
-
-        // Handle absolute and relative paths
-        match dest.is_absolute() {
-            true => { self.config.set_dest(dest); },
-            false => {
-                let dest = self.config.get_root().join(dest).to_owned();
-                self.config.set_dest(&dest);
-            }
-        }
-
-        self
-    }
-
-    pub fn get_dest(&self) -> &Path {
-        self.config.get_dest()
-    }
-
-    pub fn set_src(mut self, src: &Path) -> Self {
-
-        // Handle absolute and relative paths
-        match src.is_absolute() {
-            true => { self.config.set_src(src); },
-            false => {
-                let src = self.config.get_root().join(src).to_owned();
-                self.config.set_src(&src);
-            }
-        }
-
-        self
-    }
-
-    pub fn get_src(&self) -> &Path {
-        self.config.get_src()
-    }
-
-    pub fn set_title(mut self, title: &str) -> Self {
-        self.config.title = title.to_owned();
-        self
-    }
-
-    pub fn get_title(&self) -> &str {
-        &self.config.title
-    }
-
-    pub fn set_author(mut self, author: &str) -> Self {
-        self.config.author = author.to_owned();
-        self
-    }
-
-    pub fn get_author(&self) -> &str {
-        &self.config.author
-    }
-
-    // Construct book
-    fn parse_summary(&mut self) -> Result<(), Box<Error>> {
-        // When append becomes stable, use self.content.append() ...
-        self.content = try!(parse::construct_bookitems(&self.config.get_src().join("SUMMARY.md")));
-        Ok(())
-    }
-
-}

src/book/mod.rs

@@ -1,7 +1,860 @@
-pub mod mdbook;
-pub mod bookitem;
-pub mod bookconfig;
+//! The internal representation of a book and infrastructure for loading it from
+//! disk and building it.
+//!
+//! For examples on using `MDBook`, consult the [top-level documentation][1].
+//!
+//! [1]: ../index.html
 
-pub use self::bookitem::{BookItem, BookItems};
-pub use self::bookconfig::BookConfig;
-pub use self::mdbook::MDBook;
+#[allow(clippy::module_inception)]
+mod book;
+mod init;
+mod summary;
+
+pub use self::book::{load_book, Book, BookItem, BookItems, Chapter};
+pub use self::init::BookBuilder;
+pub use self::summary::{parse_summary, Link, SectionNumber, Summary, SummaryItem};
+
+use log::{debug, error, info, log_enabled, trace, warn};
+use std::io::Write;
+use std::path::PathBuf;
+use std::process::Command;
+use std::string::ToString;
+use tempfile::Builder as TempFileBuilder;
+use toml::Value;
+use topological_sort::TopologicalSort;
+
+use crate::errors::*;
+use crate::preprocess::{
+    CmdPreprocessor, IndexPreprocessor, LinkPreprocessor, Preprocessor, PreprocessorContext,
+};
+use crate::renderer::{CmdRenderer, HtmlHandlebars, MarkdownRenderer, RenderContext, Renderer};
+use crate::utils;
+
+use crate::config::{Config, RustEdition};
+
+/// The object used to manage and build a book.
+pub struct MDBook {
+    /// The book's root directory.
+    pub root: PathBuf,
+    /// The configuration used to tweak now a book is built.
+    pub config: Config,
+    /// A representation of the book's contents in memory.
+    pub book: Book,
+    renderers: Vec<Box<dyn Renderer>>,
+
+    /// List of pre-processors to be run on the book.
+    preprocessors: Vec<Box<dyn Preprocessor>>,
+}
+
+impl MDBook {
+    /// Load a book from its root directory on disk.
+    pub fn load<P: Into<PathBuf>>(book_root: P) -> Result<MDBook> {
+        let book_root = book_root.into();
+        let config_location = book_root.join("book.toml");
+
+        // the book.json file is no longer used, so we should emit a warning to
+        // let people know to migrate to book.toml
+        if book_root.join("book.json").exists() {
+            warn!("It appears you are still using book.json for configuration.");
+            warn!("This format is no longer used, so you should migrate to the");
+            warn!("book.toml format.");
+            warn!("Check the user guide for migration information:");
+            warn!("\thttps://rust-lang.github.io/mdBook/format/config.html");
+        }
+
+        let mut config = if config_location.exists() {
+            debug!("Loading config from {}", config_location.display());
+            Config::from_disk(&config_location)?
+        } else {
+            Config::default()
+        };
+
+        config.update_from_env();
+
+        if config
+            .html_config()
+            .map_or(false, |html| html.google_analytics.is_some())
+        {
+            warn!(
+                "The output.html.google-analytics field has been deprecated; \
+                 it will be removed in a future release.\n\
+                 Consider placing the appropriate site tag code into the \
+                 theme/head.hbs file instead.\n\
+                 The tracking code may be found in the Google Analytics Admin page.\n\
+               "
+            );
+        }
+
+        if log_enabled!(log::Level::Trace) {
+            for line in format!("Config: {:#?}", config).lines() {
+                trace!("{}", line);
+            }
+        }
+
+        MDBook::load_with_config(book_root, config)
+    }
+
+    /// Load a book from its root directory using a custom `Config`.
+    pub fn load_with_config<P: Into<PathBuf>>(book_root: P, config: Config) -> Result<MDBook> {
+        let root = book_root.into();
+
+        let src_dir = root.join(&config.book.src);
+        let book = book::load_book(&src_dir, &config.build)?;
+
+        let renderers = determine_renderers(&config);
+        let preprocessors = determine_preprocessors(&config)?;
+
+        Ok(MDBook {
+            root,
+            config,
+            book,
+            renderers,
+            preprocessors,
+        })
+    }
+
+    /// Load a book from its root directory using a custom `Config` and a custom summary.
+    pub fn load_with_config_and_summary<P: Into<PathBuf>>(
+        book_root: P,
+        config: Config,
+        summary: Summary,
+    ) -> Result<MDBook> {
+        let root = book_root.into();
+
+        let src_dir = root.join(&config.book.src);
+        let book = book::load_book_from_disk(&summary, &src_dir)?;
+
+        let renderers = determine_renderers(&config);
+        let preprocessors = determine_preprocessors(&config)?;
+
+        Ok(MDBook {
+            root,
+            config,
+            book,
+            renderers,
+            preprocessors,
+        })
+    }
+
+    /// Returns a flat depth-first iterator over the elements of the book,
+    /// it returns a [`BookItem`] enum:
+    /// `(section: String, bookitem: &BookItem)`
+    ///
+    /// ```no_run
+    /// # use mdbook::MDBook;
+    /// # use mdbook::book::BookItem;
+    /// # let book = MDBook::load("mybook").unwrap();
+    /// for item in book.iter() {
+    ///     match *item {
+    ///         BookItem::Chapter(ref chapter) => {},
+    ///         BookItem::Separator => {},
+    ///         BookItem::PartTitle(ref title) => {}
+    ///     }
+    /// }
+    ///
+    /// // would print something like this:
+    /// // 1. Chapter 1
+    /// // 1.1 Sub Chapter
+    /// // 1.2 Sub Chapter
+    /// // 2. Chapter 2
+    /// //
+    /// // etc.
+    /// ```
+    pub fn iter(&self) -> BookItems<'_> {
+        self.book.iter()
+    }
+
+    /// `init()` gives you a `BookBuilder` which you can use to setup a new book
+    /// and its accompanying directory structure.
+    ///
+    /// The `BookBuilder` creates some boilerplate files and directories to get
+    /// you started with your book.
+    ///
+    /// ```text
+    /// book-test/
+    /// ├── book
+    /// └── src
+    ///     ├── chapter_1.md
+    ///     └── SUMMARY.md
+    /// ```
+    ///
+    /// It uses the path provided as the root directory for your book, then adds
+    /// in a `src/` directory containing a `SUMMARY.md` and `chapter_1.md` file
+    /// to get you started.
+    pub fn init<P: Into<PathBuf>>(book_root: P) -> BookBuilder {
+        BookBuilder::new(book_root)
+    }
+
+    /// Tells the renderer to build our book and put it in the build directory.
+    pub fn build(&self) -> Result<()> {
+        info!("Book building has started");
+
+        for renderer in &self.renderers {
+            self.execute_build_process(&**renderer)?;
+        }
+
+        Ok(())
+    }
+
+    /// Run the entire build process for a particular [`Renderer`].
+    pub fn execute_build_process(&self, renderer: &dyn Renderer) -> Result<()> {
+        let mut preprocessed_book = self.book.clone();
+        let preprocess_ctx = PreprocessorContext::new(
+            self.root.clone(),
+            self.config.clone(),
+            renderer.name().to_string(),
+        );
+
+        for preprocessor in &self.preprocessors {
+            if preprocessor_should_run(&**preprocessor, renderer, &self.config) {
+                debug!("Running the {} preprocessor.", preprocessor.name());
+                preprocessed_book = preprocessor.run(&preprocess_ctx, preprocessed_book)?;
+            }
+        }
+
+        let name = renderer.name();
+        let build_dir = self.build_dir_for(name);
+
+        let mut render_context = RenderContext::new(
+            self.root.clone(),
+            preprocessed_book,
+            self.config.clone(),
+            build_dir,
+        );
+        render_context
+            .chapter_titles
+            .extend(preprocess_ctx.chapter_titles.borrow_mut().drain());
+
+        info!("Running the {} backend", renderer.name());
+        renderer
+            .render(&render_context)
+            .with_context(|| "Rendering failed")
+    }
+
+    /// You can change the default renderer to another one by using this method.
+    /// The only requirement is that your renderer implement the [`Renderer`]
+    /// trait.
+    pub fn with_renderer<R: Renderer + 'static>(&mut self, renderer: R) -> &mut Self {
+        self.renderers.push(Box::new(renderer));
+        self
+    }
+
+    /// Register a [`Preprocessor`] to be used when rendering the book.
+    pub fn with_preprocessor<P: Preprocessor + 'static>(&mut self, preprocessor: P) -> &mut Self {
+        self.preprocessors.push(Box::new(preprocessor));
+        self
+    }
+
+    /// Run `rustdoc` tests on the book, linking against the provided libraries.
+    pub fn test(&mut self, library_paths: Vec<&str>) -> Result<()> {
+        // test_chapter with chapter:None will run all tests.
+        self.test_chapter(library_paths, None)
+    }
+
+    /// Run `rustdoc` tests on a specific chapter of the book, linking against the provided libraries.
+    /// If `chapter` is `None`, all tests will be run.
+    pub fn test_chapter(&mut self, library_paths: Vec<&str>, chapter: Option<&str>) -> Result<()> {
+        let library_args: Vec<&str> = (0..library_paths.len())
+            .map(|_| "-L")
+            .zip(library_paths.into_iter())
+            .flat_map(|x| vec![x.0, x.1])
+            .collect();
+
+        let temp_dir = TempFileBuilder::new().prefix("mdbook-").tempdir()?;
+
+        let mut chapter_found = false;
+
+        // FIXME: Is "test" the proper renderer name to use here?
+        let preprocess_context =
+            PreprocessorContext::new(self.root.clone(), self.config.clone(), "test".to_string());
+
+        let book = LinkPreprocessor::new().run(&preprocess_context, self.book.clone())?;
+        // Index Preprocessor is disabled so that chapter paths continue to point to the
+        // actual markdown files.
+
+        let mut failed = false;
+        for item in book.iter() {
+            if let BookItem::Chapter(ref ch) = *item {
+                let chapter_path = match ch.path {
+                    Some(ref path) if !path.as_os_str().is_empty() => path,
+                    _ => continue,
+                };
+
+                if let Some(chapter) = chapter {
+                    if ch.name != chapter && chapter_path.to_str() != Some(chapter) {
+                        if chapter == "?" {
+                            info!("Skipping chapter '{}'...", ch.name);
+                        }
+                        continue;
+                    }
+                }
+                chapter_found = true;
+                info!("Testing chapter '{}': {:?}", ch.name, chapter_path);
+
+                // write preprocessed file to tempdir
+                let path = temp_dir.path().join(&chapter_path);
+                let mut tmpf = utils::fs::create_file(&path)?;
+                tmpf.write_all(ch.content.as_bytes())?;
+
+                let mut cmd = Command::new("rustdoc");
+                cmd.arg(&path).arg("--test").args(&library_args);
+
+                if let Some(edition) = self.config.rust.edition {
+                    match edition {
+                        RustEdition::E2015 => {
+                            cmd.args(&["--edition", "2015"]);
+                        }
+                        RustEdition::E2018 => {
+                            cmd.args(&["--edition", "2018"]);
+                        }
+                        RustEdition::E2021 => {
+                            cmd.args(&["--edition", "2021"]);
+                        }
+                    }
+                }
+
+                debug!("running {:?}", cmd);
+                let output = cmd.output()?;
+
+                if !output.status.success() {
+                    failed = true;
+                    error!(
+                        "rustdoc returned an error:\n\
+                        \n--- stdout\n{}\n--- stderr\n{}",
+                        String::from_utf8_lossy(&output.stdout),
+                        String::from_utf8_lossy(&output.stderr)
+                    );
+                }
+            }
+        }
+        if failed {
+            bail!("One or more tests failed");
+        }
+        if let Some(chapter) = chapter {
+            if !chapter_found {
+                bail!("Chapter not found: {}", chapter);
+            }
+        }
+        Ok(())
+    }
+
+    /// The logic for determining where a backend should put its build
+    /// artefacts.
+    ///
+    /// If there is only 1 renderer, put it in the directory pointed to by the
+    /// `build.build_dir` key in [`Config`]. If there is more than one then the
+    /// renderer gets its own directory within the main build dir.
+    ///
+    /// i.e. If there were only one renderer (in this case, the HTML renderer):
+    ///
+    /// - build/
+    ///   - index.html
+    ///   - ...
+    ///
+    /// Otherwise if there are multiple:
+    ///
+    /// - build/
+    ///   - epub/
+    ///     - my_awesome_book.epub
+    ///   - html/
+    ///     - index.html
+    ///     - ...
+    ///   - latex/
+    ///     - my_awesome_book.tex
+    ///
+    pub fn build_dir_for(&self, backend_name: &str) -> PathBuf {
+        let build_dir = self.root.join(&self.config.build.build_dir);
+
+        if self.renderers.len() <= 1 {
+            build_dir
+        } else {
+            build_dir.join(backend_name)
+        }
+    }
+
+    /// Get the directory containing this book's source files.
+    pub fn source_dir(&self) -> PathBuf {
+        self.root.join(&self.config.book.src)
+    }
+
+    /// Get the directory containing the theme resources for the book.
+    pub fn theme_dir(&self) -> PathBuf {
+        self.config
+            .html_config()
+            .unwrap_or_default()
+            .theme_dir(&self.root)
+    }
+}
+
+/// Look at the `Config` and try to figure out what renderers to use.
+fn determine_renderers(config: &Config) -> Vec<Box<dyn Renderer>> {
+    let mut renderers = Vec::new();
+
+    if let Some(output_table) = config.get("output").and_then(Value::as_table) {
+        renderers.extend(output_table.iter().map(|(key, table)| {
+            if key == "html" {
+                Box::new(HtmlHandlebars::new()) as Box<dyn Renderer>
+            } else if key == "markdown" {
+                Box::new(MarkdownRenderer::new()) as Box<dyn Renderer>
+            } else {
+                interpret_custom_renderer(key, table)
+            }
+        }));
+    }
+
+    // if we couldn't find anything, add the HTML renderer as a default
+    if renderers.is_empty() {
+        renderers.push(Box::new(HtmlHandlebars::new()));
+    }
+
+    renderers
+}
+
+const DEFAULT_PREPROCESSORS: &[&str] = &["links", "index"];
+
+fn is_default_preprocessor(pre: &dyn Preprocessor) -> bool {
+    let name = pre.name();
+    name == LinkPreprocessor::NAME || name == IndexPreprocessor::NAME
+}
+
+/// Look at the `MDBook` and try to figure out what preprocessors to run.
+fn determine_preprocessors(config: &Config) -> Result<Vec<Box<dyn Preprocessor>>> {
+    // Collect the names of all preprocessors intended to be run, and the order
+    // in which they should be run.
+    let mut preprocessor_names = TopologicalSort::<String>::new();
+
+    if config.build.use_default_preprocessors {
+        for name in DEFAULT_PREPROCESSORS {
+            preprocessor_names.insert(name.to_string());
+        }
+    }
+
+    if let Some(preprocessor_table) = config.get("preprocessor").and_then(Value::as_table) {
+        for (name, table) in preprocessor_table.iter() {
+            preprocessor_names.insert(name.to_string());
+
+            let exists = |name| {
+                (config.build.use_default_preprocessors && DEFAULT_PREPROCESSORS.contains(&name))
+                    || preprocessor_table.contains_key(name)
+            };
+
+            if let Some(before) = table.get("before") {
+                let before = before.as_array().ok_or_else(|| {
+                    Error::msg(format!(
+                        "Expected preprocessor.{}.before to be an array",
+                        name
+                    ))
+                })?;
+                for after in before {
+                    let after = after.as_str().ok_or_else(|| {
+                        Error::msg(format!(
+                            "Expected preprocessor.{}.before to contain strings",
+                            name
+                        ))
+                    })?;
+
+                    if !exists(after) {
+                        // Only warn so that preprocessors can be toggled on and off (e.g. for
+                        // troubleshooting) without having to worry about order too much.
+                        warn!(
+                            "preprocessor.{}.after contains \"{}\", which was not found",
+                            name, after
+                        );
+                    } else {
+                        preprocessor_names.add_dependency(name, after);
+                    }
+                }
+            }
+
+            if let Some(after) = table.get("after") {
+                let after = after.as_array().ok_or_else(|| {
+                    Error::msg(format!(
+                        "Expected preprocessor.{}.after to be an array",
+                        name
+                    ))
+                })?;
+                for before in after {
+                    let before = before.as_str().ok_or_else(|| {
+                        Error::msg(format!(
+                            "Expected preprocessor.{}.after to contain strings",
+                            name
+                        ))
+                    })?;
+
+                    if !exists(before) {
+                        // See equivalent warning above for rationale
+                        warn!(
+                            "preprocessor.{}.before contains \"{}\", which was not found",
+                            name, before
+                        );
+                    } else {
+                        preprocessor_names.add_dependency(before, name);
+                    }
+                }
+            }
+        }
+    }
+
+    // Now that all links have been established, queue preprocessors in a suitable order
+    let mut preprocessors = Vec::with_capacity(preprocessor_names.len());
+    // `pop_all()` returns an empty vector when no more items are not being depended upon
+    for mut names in std::iter::repeat_with(|| preprocessor_names.pop_all())
+        .take_while(|names| !names.is_empty())
+    {
+        // The `topological_sort` crate does not guarantee a stable order for ties, even across
+        // runs of the same program. Thus, we break ties manually by sorting.
+        // Careful: `str`'s default sorting, which we are implicitly invoking here, uses code point
+        // values ([1]), which may not be an alphabetical sort.
+        // As mentioned in [1], doing so depends on locale, which is not desirable for deciding
+        // preprocessor execution order.
+        // [1]: https://doc.rust-lang.org/stable/std/cmp/trait.Ord.html#impl-Ord-14
+        names.sort();
+        for name in names {
+            let preprocessor: Box<dyn Preprocessor> = match name.as_str() {
+                "links" => Box::new(LinkPreprocessor::new()),
+                "index" => Box::new(IndexPreprocessor::new()),
+                _ => {
+                    // The only way to request a custom preprocessor is through the `preprocessor`
+                    // table, so it must exist, be a table, and contain the key.
+                    let table = &config.get("preprocessor").unwrap().as_table().unwrap()[&name];
+                    let command = get_custom_preprocessor_cmd(&name, table);
+                    Box::new(CmdPreprocessor::new(name, command))
+                }
+            };
+            preprocessors.push(preprocessor);
+        }
+    }
+
+    // "If `pop_all` returns an empty vector and `len` is not 0, there are cyclic dependencies."
+    // Normally, `len() == 0` is equivalent to `is_empty()`, so we'll use that.
+    if preprocessor_names.is_empty() {
+        Ok(preprocessors)
+    } else {
+        Err(Error::msg("Cyclic dependency detected in preprocessors"))
+    }
+}
+
+fn get_custom_preprocessor_cmd(key: &str, table: &Value) -> String {
+    table
+        .get("command")
+        .and_then(Value::as_str)
+        .map(ToString::to_string)
+        .unwrap_or_else(|| format!("mdbook-{}", key))
+}
+
+fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
+    // look for the `command` field, falling back to using the key
+    // prepended by "mdbook-"
+    let table_dot_command = table
+        .get("command")
+        .and_then(Value::as_str)
+        .map(ToString::to_string);
+
+    let command = table_dot_command.unwrap_or_else(|| format!("mdbook-{}", key));
+
+    Box::new(CmdRenderer::new(key.to_string(), command))
+}
+
+/// Check whether we should run a particular `Preprocessor` in combination
+/// with the renderer, falling back to `Preprocessor::supports_renderer()`
+/// method if the user doesn't say anything.
+///
+/// The `build.use-default-preprocessors` config option can be used to ensure
+/// default preprocessors always run if they support the renderer.
+fn preprocessor_should_run(
+    preprocessor: &dyn Preprocessor,
+    renderer: &dyn Renderer,
+    cfg: &Config,
+) -> bool {
+    // default preprocessors should be run by default (if supported)
+    if cfg.build.use_default_preprocessors && is_default_preprocessor(preprocessor) {
+        return preprocessor.supports_renderer(renderer.name());
+    }
+
+    let key = format!("preprocessor.{}.renderers", preprocessor.name());
+    let renderer_name = renderer.name();
+
+    if let Some(Value::Array(ref explicit_renderers)) = cfg.get(&key) {
+        return explicit_renderers
+            .iter()
+            .filter_map(Value::as_str)
+            .any(|name| name == renderer_name);
+    }
+
+    preprocessor.supports_renderer(renderer_name)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::str::FromStr;
+    use toml::value::{Table, Value};
+
+    #[test]
+    fn config_defaults_to_html_renderer_if_empty() {
+        let cfg = Config::default();
+
+        // make sure we haven't got anything in the `output` table
+        assert!(cfg.get("output").is_none());
+
+        let got = determine_renderers(&cfg);
+
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].name(), "html");
+    }
+
+    #[test]
+    fn add_a_random_renderer_to_the_config() {
+        let mut cfg = Config::default();
+        cfg.set("output.random", Table::new()).unwrap();
+
+        let got = determine_renderers(&cfg);
+
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].name(), "random");
+    }
+
+    #[test]
+    fn add_a_random_renderer_with_custom_command_to_the_config() {
+        let mut cfg = Config::default();
+
+        let mut table = Table::new();
+        table.insert("command".to_string(), Value::String("false".to_string()));
+        cfg.set("output.random", table).unwrap();
+
+        let got = determine_renderers(&cfg);
+
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].name(), "random");
+    }
+
+    #[test]
+    fn config_defaults_to_link_and_index_preprocessor_if_not_set() {
+        let cfg = Config::default();
+
+        // make sure we haven't got anything in the `preprocessor` table
+        assert!(cfg.get("preprocessor").is_none());
+
+        let got = determine_preprocessors(&cfg);
+
+        assert!(got.is_ok());
+        assert_eq!(got.as_ref().unwrap().len(), 2);
+        assert_eq!(got.as_ref().unwrap()[0].name(), "index");
+        assert_eq!(got.as_ref().unwrap()[1].name(), "links");
+    }
+
+    #[test]
+    fn use_default_preprocessors_works() {
+        let mut cfg = Config::default();
+        cfg.build.use_default_preprocessors = false;
+
+        let got = determine_preprocessors(&cfg).unwrap();
+
+        assert_eq!(got.len(), 0);
+    }
+
+    #[test]
+    fn can_determine_third_party_preprocessors() {
+        let cfg_str = r#"
+        [book]
+        title = "Some Book"
+
+        [preprocessor.random]
+
+        [build]
+        build-dir = "outputs"
+        create-missing = false
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        // make sure the `preprocessor.random` table exists
+        assert!(cfg.get_preprocessor("random").is_some());
+
+        let got = determine_preprocessors(&cfg).unwrap();
+
+        assert!(got.into_iter().any(|p| p.name() == "random"));
+    }
+
+    #[test]
+    fn preprocessors_can_provide_their_own_commands() {
+        let cfg_str = r#"
+        [preprocessor.random]
+        command = "python random.py"
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        // make sure the `preprocessor.random` table exists
+        let random = cfg.get_preprocessor("random").unwrap();
+        let random = get_custom_preprocessor_cmd("random", &Value::Table(random.clone()));
+
+        assert_eq!(random, "python random.py");
+    }
+
+    #[test]
+    fn preprocessor_before_must_be_array() {
+        let cfg_str = r#"
+        [preprocessor.random]
+        before = 0
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        assert!(determine_preprocessors(&cfg).is_err());
+    }
+
+    #[test]
+    fn preprocessor_after_must_be_array() {
+        let cfg_str = r#"
+        [preprocessor.random]
+        after = 0
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        assert!(determine_preprocessors(&cfg).is_err());
+    }
+
+    #[test]
+    fn preprocessor_order_is_honored() {
+        let cfg_str = r#"
+        [preprocessor.random]
+        before = [ "last" ]
+        after = [ "index" ]
+
+        [preprocessor.last]
+        after = [ "links", "index" ]
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        let preprocessors = determine_preprocessors(&cfg).unwrap();
+        let index = |name| {
+            preprocessors
+                .iter()
+                .enumerate()
+                .find(|(_, preprocessor)| preprocessor.name() == name)
+                .unwrap()
+                .0
+        };
+        let assert_before = |before, after| {
+            if index(before) >= index(after) {
+                eprintln!("Preprocessor order:");
+                for preprocessor in &preprocessors {
+                    eprintln!("  {}", preprocessor.name());
+                }
+                panic!("{} should come before {}", before, after);
+            }
+        };
+
+        assert_before("index", "random");
+        assert_before("index", "last");
+        assert_before("random", "last");
+        assert_before("links", "last");
+    }
+
+    #[test]
+    fn cyclic_dependencies_are_detected() {
+        let cfg_str = r#"
+        [preprocessor.links]
+        before = [ "index" ]
+
+        [preprocessor.index]
+        before = [ "links" ]
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        assert!(determine_preprocessors(&cfg).is_err());
+    }
+
+    #[test]
+    fn dependencies_dont_register_undefined_preprocessors() {
+        let cfg_str = r#"
+        [preprocessor.links]
+        before = [ "random" ]
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        let preprocessors = determine_preprocessors(&cfg).unwrap();
+
+        assert!(!preprocessors
+            .iter()
+            .any(|preprocessor| preprocessor.name() == "random"));
+    }
+
+    #[test]
+    fn dependencies_dont_register_builtin_preprocessors_if_disabled() {
+        let cfg_str = r#"
+        [preprocessor.random]
+        before = [ "links" ]
+
+        [build]
+        use-default-preprocessors = false
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        let preprocessors = determine_preprocessors(&cfg).unwrap();
+
+        assert!(!preprocessors
+            .iter()
+            .any(|preprocessor| preprocessor.name() == "links"));
+    }
+
+    #[test]
+    fn config_respects_preprocessor_selection() {
+        let cfg_str = r#"
+        [preprocessor.links]
+        renderers = ["html"]
+        "#;
+
+        let cfg = Config::from_str(cfg_str).unwrap();
+
+        // double-check that we can access preprocessor.links.renderers[0]
+        let html = cfg
+            .get_preprocessor("links")
+            .and_then(|links| links.get("renderers"))
+            .and_then(Value::as_array)
+            .and_then(|renderers| renderers.get(0))
+            .and_then(Value::as_str)
+            .unwrap();
+        assert_eq!(html, "html");
+        let html_renderer = HtmlHandlebars::default();
+        let pre = LinkPreprocessor::new();
+
+        let should_run = preprocessor_should_run(&pre, &html_renderer, &cfg);
+        assert!(should_run);
+    }
+
+    struct BoolPreprocessor(bool);
+    impl Preprocessor for BoolPreprocessor {
+        fn name(&self) -> &str {
+            "bool-preprocessor"
+        }
+
+        fn run(&self, _ctx: &PreprocessorContext, _book: Book) -> Result<Book> {
+            unimplemented!()
+        }
+
+        fn supports_renderer(&self, _renderer: &str) -> bool {
+            self.0
+        }
+    }
+
+    #[test]
+    fn preprocessor_should_run_falls_back_to_supports_renderer_method() {
+        let cfg = Config::default();
+        let html = HtmlHandlebars::new();
+
+        let should_be = true;
+        let got = preprocessor_should_run(&BoolPreprocessor(should_be), &html, &cfg);
+        assert_eq!(got, should_be);
+
+        let should_be = false;
+        let got = preprocessor_should_run(&BoolPreprocessor(should_be), &html, &cfg);
+        assert_eq!(got, should_be);
+    }
+}

src/cmd/build.rs

@@ -0,0 +1,38 @@
+use super::command_prelude::*;
+use crate::{get_book_dir, open};
+use mdbook::errors::Result;
+use mdbook::MDBook;
+use std::path::PathBuf;
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> Command {
+    Command::new("build")
+        .about("Builds a book from its markdown files")
+        .arg_dest_dir()
+        .arg_root_dir()
+        .arg_open()
+}
+
+// Build command implementation
+pub fn execute(args: &ArgMatches) -> Result<()> {
+    let book_dir = get_book_dir(args);
+    let mut book = MDBook::load(&book_dir)?;
+
+    if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
+        book.config.build.build_dir = dest_dir.into();
+    }
+
+    book.build()?;
+
+    if args.get_flag("open") {
+        // FIXME: What's the right behaviour if we don't use the HTML renderer?
+        let path = book.build_dir_for("html").join("index.html");
+        if !path.exists() {
+            error!("No chapter available to open");
+            std::process::exit(1)
+        }
+        open(path);
+    }
+
+    Ok(())
+}

src/cmd/clean.rs

@@ -0,0 +1,32 @@
+use super::command_prelude::*;
+use crate::get_book_dir;
+use anyhow::Context;
+use mdbook::MDBook;
+use std::fs;
+use std::path::PathBuf;
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> Command {
+    Command::new("clean")
+        .about("Deletes a built book")
+        .arg_dest_dir()
+        .arg_root_dir()
+}
+
+// Clean command implementation
+pub fn execute(args: &ArgMatches) -> mdbook::errors::Result<()> {
+    let book_dir = get_book_dir(args);
+    let book = MDBook::load(&book_dir)?;
+
+    let dir_to_remove = match args.get_one::<PathBuf>("dest-dir") {
+        Some(dest_dir) => dest_dir.into(),
+        None => book.root.join(&book.config.build.build_dir),
+    };
+
+    if dir_to_remove.exists() {
+        fs::remove_dir_all(&dir_to_remove)
+            .with_context(|| "Unable to remove the build directory")?;
+    }
+
+    Ok(())
+}

src/cmd/command_prelude.rs

@@ -0,0 +1,45 @@
+//! Helpers for building the command-line arguments for commands.
+
+pub use clap::{arg, Arg, ArgMatches, Command};
+use std::path::PathBuf;
+
+pub trait CommandExt: Sized {
+    fn _arg(self, arg: Arg) -> Self;
+
+    fn arg_dest_dir(self) -> Self {
+        self._arg(
+            Arg::new("dest-dir")
+                .short('d')
+                .long("dest-dir")
+                .value_name("dest-dir")
+                .value_parser(clap::value_parser!(PathBuf))
+                .help(
+                    "Output directory for the book\n\
+                    Relative paths are interpreted relative to the book's root directory.\n\
+                    If omitted, mdBook uses build.build-dir from book.toml \
+                    or defaults to `./book`.",
+                ),
+        )
+    }
+
+    fn arg_root_dir(self) -> Self {
+        self._arg(
+            Arg::new("dir")
+                .help(
+                    "Root directory for the book\n\
+                    (Defaults to the current directory when omitted)",
+                )
+                .value_parser(clap::value_parser!(PathBuf)),
+        )
+    }
+
+    fn arg_open(self) -> Self {
+        self._arg(arg!(-o --open "Opens the compiled book in a web browser"))
+    }
+}
+
+impl CommandExt for Command {
+    fn _arg(self, arg: Arg) -> Self {
+        self.arg(arg)
+    }
+}

src/cmd/init.rs

@@ -0,0 +1,118 @@
+use crate::get_book_dir;
+use clap::{arg, ArgMatches, Command as ClapCommand};
+use mdbook::config;
+use mdbook::errors::Result;
+use mdbook::MDBook;
+use std::io;
+use std::io::Write;
+use std::process::Command;
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> ClapCommand {
+    ClapCommand::new("init")
+        .about("Creates the boilerplate structure and files for a new book")
+        .arg(
+            arg!([dir]
+                "Directory to create the book in\n\
+                (Defaults to the current directory when omitted)"
+            )
+            .value_parser(clap::value_parser!(std::path::PathBuf)),
+        )
+        .arg(arg!(--theme "Copies the default theme into your source folder"))
+        .arg(arg!(--force "Skips confirmation prompts"))
+        .arg(arg!(--title <title> "Sets the book title"))
+        .arg(
+            arg!(--ignore <ignore> "Creates a VCS ignore file (i.e. .gitignore)")
+                .value_parser(["none", "git"]),
+        )
+}
+
+// Init command implementation
+pub fn execute(args: &ArgMatches) -> Result<()> {
+    let book_dir = get_book_dir(args);
+    let mut builder = MDBook::init(&book_dir);
+    let mut config = config::Config::default();
+    // If flag `--theme` is present, copy theme to src
+    if args.get_flag("theme") {
+        let theme_dir = book_dir.join("theme");
+        println!();
+        println!("Copying the default theme to {}", theme_dir.display());
+        // Skip this if `--force` is present
+        if !args.get_flag("force") && theme_dir.exists() {
+            println!("This could potentially overwrite files already present in that directory.");
+            print!("\nAre you sure you want to continue? (y/n) ");
+
+            // Read answer from user and exit if it's not 'yes'
+            if confirm() {
+                builder.copy_theme(true);
+            }
+        } else {
+            builder.copy_theme(true);
+        }
+    }
+
+    if let Some(ignore) = args.get_one::<String>("ignore").map(|s| s.as_str()) {
+        match ignore {
+            "git" => builder.create_gitignore(true),
+            _ => builder.create_gitignore(false),
+        };
+    } else {
+        println!("\nDo you want a .gitignore to be created? (y/n)");
+        if confirm() {
+            builder.create_gitignore(true);
+        }
+    }
+
+    config.book.title = if args.contains_id("title") {
+        args.get_one::<String>("title").map(String::from)
+    } else {
+        request_book_title()
+    };
+
+    if let Some(author) = get_author_name() {
+        debug!("Obtained user name from gitconfig: {:?}", author);
+        config.book.authors.push(author);
+        builder.with_config(config);
+    }
+
+    builder.build()?;
+    println!("\nAll done, no errors...");
+
+    Ok(())
+}
+
+/// Obtains author name from git config file by running the `git config` command.
+fn get_author_name() -> Option<String> {
+    let output = Command::new("git")
+        .args(&["config", "--get", "user.name"])
+        .output()
+        .ok()?;
+
+    if output.status.success() {
+        Some(String::from_utf8_lossy(&output.stdout).trim().to_owned())
+    } else {
+        None
+    }
+}
+
+/// Request book title from user and return if provided.
+fn request_book_title() -> Option<String> {
+    println!("What title would you like to give the book? ");
+    io::stdout().flush().unwrap();
+    let mut resp = String::new();
+    io::stdin().read_line(&mut resp).unwrap();
+    let resp = resp.trim();
+    if resp.is_empty() {
+        None
+    } else {
+        Some(resp.into())
+    }
+}
+
+// Simple function for user confirmation
+fn confirm() -> bool {
+    io::stdout().flush().unwrap();
+    let mut s = String::new();
+    io::stdin().read_line(&mut s).ok();
+    matches!(&*s.trim(), "Y" | "y" | "yes" | "Yes")
+}

src/cmd/mod.rs

@@ -0,0 +1,11 @@
+//! Subcommand modules for the `mdbook` binary.
+
+pub mod build;
+pub mod clean;
+pub mod command_prelude;
+pub mod init;
+#[cfg(feature = "serve")]
+pub mod serve;
+pub mod test;
+#[cfg(feature = "watch")]
+pub mod watch;

src/cmd/serve.rs

@@ -0,0 +1,164 @@
+use super::command_prelude::*;
+#[cfg(feature = "watch")]
+use super::watch;
+use crate::{get_book_dir, open};
+use clap::builder::NonEmptyStringValueParser;
+use futures_util::sink::SinkExt;
+use futures_util::StreamExt;
+use mdbook::errors::*;
+use mdbook::utils;
+use mdbook::utils::fs::get_404_output_file;
+use mdbook::MDBook;
+use std::net::{SocketAddr, ToSocketAddrs};
+use std::path::PathBuf;
+use tokio::sync::broadcast;
+use warp::ws::Message;
+use warp::Filter;
+
+/// The HTTP endpoint for the websocket used to trigger reloads when a file changes.
+const LIVE_RELOAD_ENDPOINT: &str = "__livereload";
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> Command {
+    Command::new("serve")
+        .about("Serves a book at http://localhost:3000, and rebuilds it on changes")
+        .arg_dest_dir()
+        .arg_root_dir()
+        .arg(
+            Arg::new("hostname")
+                .short('n')
+                .long("hostname")
+                .num_args(1)
+                .default_value("localhost")
+                .value_parser(NonEmptyStringValueParser::new())
+                .help("Hostname to listen on for HTTP connections"),
+        )
+        .arg(
+            Arg::new("port")
+                .short('p')
+                .long("port")
+                .num_args(1)
+                .default_value("3000")
+                .value_parser(NonEmptyStringValueParser::new())
+                .help("Port to use for HTTP connections"),
+        )
+        .arg_open()
+}
+
+// Serve command implementation
+pub fn execute(args: &ArgMatches) -> Result<()> {
+    let book_dir = get_book_dir(args);
+    let mut book = MDBook::load(&book_dir)?;
+
+    let port = args.get_one::<String>("port").unwrap();
+    let hostname = args.get_one::<String>("hostname").unwrap();
+    let open_browser = args.get_flag("open");
+
+    let address = format!("{}:{}", hostname, port);
+
+    let update_config = |book: &mut MDBook| {
+        book.config
+            .set("output.html.live-reload-endpoint", LIVE_RELOAD_ENDPOINT)
+            .expect("live-reload-endpoint update failed");
+        if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+        // Override site-url for local serving of the 404 file
+        book.config.set("output.html.site-url", "/").unwrap();
+    };
+    update_config(&mut book);
+    book.build()?;
+
+    let sockaddr: SocketAddr = address
+        .to_socket_addrs()?
+        .next()
+        .ok_or_else(|| anyhow::anyhow!("no address found for {}", address))?;
+    let build_dir = book.build_dir_for("html");
+    let input_404 = book
+        .config
+        .get("output.html.input-404")
+        .and_then(toml::Value::as_str)
+        .map(ToString::to_string);
+    let file_404 = get_404_output_file(&input_404);
+
+    // A channel used to broadcast to any websockets to reload when a file changes.
+    let (tx, _rx) = tokio::sync::broadcast::channel::<Message>(100);
+
+    let reload_tx = tx.clone();
+    let thread_handle = std::thread::spawn(move || {
+        serve(build_dir, sockaddr, reload_tx, &file_404);
+    });
+
+    let serving_url = format!("http://{}", address);
+    info!("Serving on: {}", serving_url);
+
+    if open_browser {
+        open(serving_url);
+    }
+
+    #[cfg(feature = "watch")]
+    watch::trigger_on_change(&book, move |paths, book_dir| {
+        info!("Files changed: {:?}", paths);
+        info!("Building book...");
+
+        // FIXME: This area is really ugly because we need to re-set livereload :(
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
+
+        if let Err(e) = result {
+            error!("Unable to load the book");
+            utils::log_backtrace(&e);
+        } else {
+            let _ = tx.send(Message::text("reload"));
+        }
+    });
+
+    let _ = thread_handle.join();
+
+    Ok(())
+}
+
+#[tokio::main]
+async fn serve(
+    build_dir: PathBuf,
+    address: SocketAddr,
+    reload_tx: broadcast::Sender<Message>,
+    file_404: &str,
+) {
+    // A warp Filter which captures `reload_tx` and provides an `rx` copy to
+    // receive reload messages.
+    let sender = warp::any().map(move || reload_tx.subscribe());
+
+    // A warp Filter to handle the livereload endpoint. This upgrades to a
+    // websocket, and then waits for any filesystem change notifications, and
+    // relays them over the websocket.
+    let livereload = warp::path(LIVE_RELOAD_ENDPOINT)
+        .and(warp::ws())
+        .and(sender)
+        .map(|ws: warp::ws::Ws, mut rx: broadcast::Receiver<Message>| {
+            ws.on_upgrade(move |ws| async move {
+                let (mut user_ws_tx, _user_ws_rx) = ws.split();
+                trace!("websocket got connection");
+                if let Ok(m) = rx.recv().await {
+                    trace!("notify of reload");
+                    let _ = user_ws_tx.send(m).await;
+                }
+            })
+        });
+    // A warp Filter that serves from the filesystem.
+    let book_route = warp::fs::dir(build_dir.clone());
+    // The fallback route for 404 errors
+    let fallback_route = warp::fs::file(build_dir.join(file_404))
+        .map(|reply| warp::reply::with_status(reply, warp::http::StatusCode::NOT_FOUND));
+    let routes = livereload.or(book_route).or(fallback_route);
+
+    std::panic::set_hook(Box::new(move |panic_info| {
+        // exit if serve panics
+        error!("Unable to serve: {}", panic_info);
+        std::process::exit(1);
+    }));
+
+    warp::serve(routes).run(address).await;
+}

src/cmd/test.rs

@@ -0,0 +1,58 @@
+use super::command_prelude::*;
+use crate::get_book_dir;
+use clap::builder::NonEmptyStringValueParser;
+use clap::{Arg, ArgAction, ArgMatches, Command};
+use mdbook::errors::Result;
+use mdbook::MDBook;
+use std::path::PathBuf;
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> Command {
+    Command::new("test")
+        .about("Tests that a book's Rust code samples compile")
+        // FIXME: --dest-dir is unused by the test command, it should be removed
+        .arg_dest_dir()
+        .arg_root_dir()
+        .arg(
+            Arg::new("chapter")
+                .short('c')
+                .long("chapter")
+                .value_name("chapter"),
+        )
+        .arg(
+            Arg::new("library-path")
+                .short('L')
+                .long("library-path")
+                .value_name("dir")
+                .value_delimiter(',')
+                .value_parser(NonEmptyStringValueParser::new())
+                .action(ArgAction::Append)
+                .help(
+                    "A comma-separated list of directories to add to the crate \
+                    search path when building tests",
+                ),
+        )
+}
+
+// test command implementation
+pub fn execute(args: &ArgMatches) -> Result<()> {
+    let library_paths: Vec<&str> = args
+        .get_many("library-path")
+        .map(|it| it.map(String::as_str).collect())
+        .unwrap_or_default();
+
+    let chapter: Option<&str> = args.get_one::<String>("chapter").map(|s| s.as_str());
+
+    let book_dir = get_book_dir(args);
+    let mut book = MDBook::load(&book_dir)?;
+
+    if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
+        book.config.build.build_dir = dest_dir.to_path_buf();
+    }
+    match chapter {
+        Some(_) => book.test_chapter(library_paths, chapter),
+        None => book.test(library_paths),
+    }?;
+
+    Ok(())
+}

src/cmd/watch.rs

@@ -0,0 +1,180 @@
+use super::command_prelude::*;
+use crate::{get_book_dir, open};
+use mdbook::errors::Result;
+use mdbook::utils;
+use mdbook::MDBook;
+use std::path::{Path, PathBuf};
+use std::sync::mpsc::channel;
+use std::thread::sleep;
+use std::time::Duration;
+
+// Create clap subcommand arguments
+pub fn make_subcommand() -> Command {
+    Command::new("watch")
+        .about("Watches a book's files and rebuilds it on changes")
+        .arg_dest_dir()
+        .arg_root_dir()
+        .arg_open()
+}
+
+// Watch command implementation
+pub fn execute(args: &ArgMatches) -> Result<()> {
+    let book_dir = get_book_dir(args);
+    let mut book = MDBook::load(&book_dir)?;
+
+    let update_config = |book: &mut MDBook| {
+        if let Some(dest_dir) = args.get_one::<PathBuf>("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+    };
+    update_config(&mut book);
+
+    if args.get_flag("open") {
+        book.build()?;
+        let path = book.build_dir_for("html").join("index.html");
+        if !path.exists() {
+            error!("No chapter available to open");
+            std::process::exit(1)
+        }
+        open(path);
+    }
+
+    trigger_on_change(&book, |paths, book_dir| {
+        info!("Files changed: {:?}\nBuilding book...\n", paths);
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
+
+        if let Err(e) = result {
+            error!("Unable to build the book");
+            utils::log_backtrace(&e);
+        }
+    });
+
+    Ok(())
+}
+
+fn remove_ignored_files(book_root: &Path, paths: &[PathBuf]) -> Vec<PathBuf> {
+    if paths.is_empty() {
+        return vec![];
+    }
+
+    match find_gitignore(book_root) {
+        Some(gitignore_path) => {
+            match gitignore::File::new(gitignore_path.as_path()) {
+                Ok(exclusion_checker) => filter_ignored_files(exclusion_checker, paths),
+                Err(_) => {
+                    // We're unable to read the .gitignore file, so we'll silently allow everything.
+                    // Please see discussion: https://github.com/rust-lang/mdBook/pull/1051
+                    paths.iter().map(|path| path.to_path_buf()).collect()
+                }
+            }
+        }
+        None => {
+            // There is no .gitignore file.
+            paths.iter().map(|path| path.to_path_buf()).collect()
+        }
+    }
+}
+
+fn find_gitignore(book_root: &Path) -> Option<PathBuf> {
+    book_root
+        .ancestors()
+        .map(|p| p.join(".gitignore"))
+        .find(|p| p.exists())
+}
+
+fn filter_ignored_files(exclusion_checker: gitignore::File, paths: &[PathBuf]) -> Vec<PathBuf> {
+    paths
+        .iter()
+        .filter(|path| match exclusion_checker.is_excluded(path) {
+            Ok(exclude) => !exclude,
+            Err(error) => {
+                warn!(
+                    "Unable to determine if {:?} is excluded: {:?}. Including it.",
+                    &path, error
+                );
+                true
+            }
+        })
+        .map(|path| path.to_path_buf())
+        .collect()
+}
+
+/// Calls the closure when a book source file is changed, blocking indefinitely.
+pub fn trigger_on_change<F>(book: &MDBook, closure: F)
+where
+    F: Fn(Vec<PathBuf>, &Path),
+{
+    use notify::RecursiveMode::*;
+
+    // Create a channel to receive the events.
+    let (tx, rx) = channel();
+
+    let mut debouncer = match notify_debouncer_mini::new_debouncer(Duration::from_secs(1), None, tx)
+    {
+        Ok(d) => d,
+        Err(e) => {
+            error!("Error while trying to watch the files:\n\n\t{:?}", e);
+            std::process::exit(1)
+        }
+    };
+    let watcher = debouncer.watcher();
+
+    // Add the source directory to the watcher
+    if let Err(e) = watcher.watch(&book.source_dir(), Recursive) {
+        error!("Error while watching {:?}:\n    {:?}", book.source_dir(), e);
+        std::process::exit(1);
+    };
+
+    let _ = watcher.watch(&book.theme_dir(), Recursive);
+
+    // Add the book.toml file to the watcher if it exists
+    let _ = watcher.watch(&book.root.join("book.toml"), NonRecursive);
+
+    for dir in &book.config.build.extra_watch_dirs {
+        let path = dir.canonicalize().unwrap();
+        if let Err(e) = watcher.watch(&path, Recursive) {
+            error!(
+                "Error while watching extra directory {:?}:\n    {:?}",
+                path, e
+            );
+            std::process::exit(1);
+        }
+    }
+
+    info!("Listening for changes...");
+
+    loop {
+        let first_event = rx.recv().unwrap();
+        sleep(Duration::from_millis(50));
+        let other_events = rx.try_iter();
+
+        let all_events = std::iter::once(first_event).chain(other_events);
+
+        let paths: Vec<_> = all_events
+            .filter_map(|event| match event {
+                Ok(events) => Some(events),
+                Err(errors) => {
+                    for error in errors {
+                        log::warn!("error while watching for changes: {error}");
+                    }
+                    None
+                }
+            })
+            .flatten()
+            .map(|event| event.path)
+            .collect();
+
+        // If we are watching files outside the current repository (via extra-watch-dirs), then they are definitionally
+        // ignored by gitignore. So we handle this case by including such files into the watched paths list.
+        let any_external_paths = paths.iter().filter(|p| !p.starts_with(&book.root)).cloned();
+        let mut paths = remove_ignored_files(&book.root, &paths[..]);
+        paths.extend(any_external_paths);
+
+        if !paths.is_empty() {
+            closure(paths, &book.root);
+        }
+    }
+}

src/lib.rs

@@ -1,83 +1,108 @@
 //! # mdBook
 //!
-//! **mdBook** is similar to Gitbook but implemented in Rust.
-//! It offers a command line interface, but can also be used as a regular crate.
+//! **mdBook** is a tool for rendering a collection of markdown documents into
+//! a form more suitable for end users like HTML or EPUB.  It offers a command
+//! line interface, but this crate can be used if more control is required.
 //!
-//! This is the API doc, but you can find a [less "low-level" documentation here](../index.html) that
-//! contains information about the command line tool, format, structure etc.
-//! It is also rendered with mdBook to showcase the features and default theme.
+//! This is the API doc, the [user guide] is also available if you want
+//! information about the command line tool, format, structure etc. It is also
+//! rendered with mdBook to showcase the features and default theme.
 //!
 //! Some reasons why you would want to use the crate (over the cli):
 //!
 //! - Integrate mdbook in a current project
 //! - Extend the capabilities of mdBook
 //! - Do some processing or test before building your book
-//! - Write a new Renderer
+//! - Accessing the public API to help create a new Renderer
 //! - ...
 //!
-//! ## Example
+//! > **Note:** While we try to ensure `mdbook`'s command-line interface and
+//! > behaviour are backwards compatible, the tool's internals are still
+//! > evolving and being iterated on. If you wish to prevent accidental
+//! > breakages it is recommended to pin any tools building on top of the
+//! > `mdbook` crate to a specific release.
 //!
-//! ```no_run
-//! extern crate mdbook;
+//! # Examples
 //!
+//! If creating a new book from scratch, you'll want to get a `BookBuilder` via
+//! the `MDBook::init()` method.
+//!
+//! ```rust,no_run
 //! use mdbook::MDBook;
-//! use std::path::Path;
+//! use mdbook::config::Config;
 //!
-//! fn main() {
-//!     let mut book =  MDBook::new(Path::new("my-book"))   // Path to root
-//!                         .set_src(Path::new("src"))      // Path from root to source directory
-//!                         .set_dest(Path::new("book"))    // Path from root to output directory
-//!                         .read_config();                 // Parse book.json file for configuration
+//! let root_dir = "/path/to/book/root";
 //!
-//!     book.build().unwrap();                              // Render the book
-//! }
+//! // create a default config and change a couple things
+//! let mut cfg = Config::default();
+//! cfg.book.title = Some("My Book".to_string());
+//! cfg.book.authors.push("Michael-F-Bryan".to_string());
+//!
+//! MDBook::init(root_dir)
+//!     .create_gitignore(true)
+//!     .with_config(cfg)
+//!     .build()
+//!     .expect("Book generation failed");
 //! ```
 //!
-//! ## Implementing a new Renderer
+//! You can also load an existing book and build it.
 //!
-//! If you want to create a new renderer for mdBook, the only thing you have to do is to implement
-//! the [Renderer trait](renderer/renderer/trait.Renderer.html)
+//! ```rust,no_run
+//! use mdbook::MDBook;
 //!
-//! And then you can swap in your renderer like this:
+//! let root_dir = "/path/to/book/root";
 //!
-//! ```no_run
-//! # extern crate mdbook;
-//! #
-//! # use mdbook::MDBook;
-//! # use mdbook::renderer::HtmlHandlebars;
-//! # use std::path::Path;
-//! #
-//! # fn main() {
-//! #   let your_renderer = HtmlHandlebars::new();
-//! #
-//!     let book =  MDBook::new(Path::new("my-book")).set_renderer(Box::new(your_renderer));
-//! # }
+//! let mut md = MDBook::load(root_dir)
+//!     .expect("Unable to load the book");
+//! md.build().expect("Building failed");
 //! ```
-//! If you make a renderer, you get the book constructed in form of `Vec<BookItems>` and you get
-//! the book config in a `BookConfig` struct.
 //!
-//! It's your responsability to create the necessary files in the correct directories.
+//! ## Implementing a new Backend
 //!
-//! ## utils
+//! `mdbook` has a fairly flexible mechanism for creating additional backends
+//! for your book. The general idea is you'll add an extra table in the book's
+//! `book.toml` which specifies an executable to be invoked by `mdbook`. This
+//! executable will then be called during a build, with an in-memory
+//! representation ([`RenderContext`]) of the book being passed to the
+//! subprocess via `stdin`.
 //!
-//! I have regrouped some useful functions in the [utils](utils/index.html) module, like the following function
+//! The [`RenderContext`] gives the backend access to the contents of
+//! `book.toml` and lets it know which directory all generated artefacts should
+//! be placed in. For a much more in-depth explanation, consult the [relevant
+//! chapter] in the *For Developers* section of the user guide.
 //!
-//! ```ignore
-//! utils::create_path(path: &Path)
-//! ```
-//! This function creates all the directories in a given path if they do not exist
+//! To make creating a backend easier, the `mdbook` crate can be imported
+//! directly, making deserializing the `RenderContext` easy and giving you
+//! access to the various methods for working with the [`Config`].
 //!
-//! Make sure to take a look at it.
+//! [user guide]: https://rust-lang.github.io/mdBook/
+//! [`RenderContext`]: renderer::RenderContext
+//! [relevant chapter]: https://rust-lang.github.io/mdBook/for_developers/backends.html
+//! [`Config`]: config::Config
+
+#![deny(missing_docs)]
+#![deny(rust_2018_idioms)]
 
-#[macro_use]
-pub mod macros;
 pub mod book;
-mod parse;
+pub mod config;
+pub mod preprocess;
 pub mod renderer;
 pub mod theme;
 pub mod utils;
 
-pub use book::MDBook;
-pub use book::BookItem;
-pub use book::BookConfig;
-pub use renderer::Renderer;
+/// The current version of `mdbook`.
+///
+/// This is provided as a way for custom preprocessors and renderers to do
+/// compatibility checks.
+pub const MDBOOK_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+pub use crate::book::BookItem;
+pub use crate::book::MDBook;
+pub use crate::config::Config;
+pub use crate::renderer::Renderer;
+
+/// The error types used through out this crate.
+pub mod errors {
+    pub(crate) use anyhow::{bail, ensure, Context};
+    pub use anyhow::{Error, Result};
+}

src/macros.rs

@@ -1,23 +0,0 @@
-#[cfg(feature = "debug")]
-macro_rules! debug {
-    ($fmt:expr) => (println!($fmt));
-    ($fmt:expr, $($arg:tt)*) => (println!($fmt, $($arg)*));
-}
-
-#[cfg(not(feature = "debug"))]
-macro_rules! debug {
-    ($fmt:expr) => ();
-    ($fmt:expr, $($arg:tt)*) => ();
-}
-
-#[cfg(feature = "output")]
-macro_rules! output {
-    ($fmt:expr) => (println!($fmt));
-    ($fmt:expr, $($arg:tt)*) => (println!($fmt, $($arg)*));
-}
-
-#[cfg(not(feature = "output"))]
-macro_rules! output {
-    ($fmt:expr) => ();
-    ($fmt:expr, $($arg:tt)*) => ();
-}

src/main.rs

@@ -0,0 +1,146 @@
+#[macro_use]
+extern crate clap;
+#[macro_use]
+extern crate log;
+
+use anyhow::anyhow;
+use chrono::Local;
+use clap::{Arg, ArgMatches, Command};
+use clap_complete::Shell;
+use env_logger::Builder;
+use log::LevelFilter;
+use mdbook::utils;
+use std::env;
+use std::ffi::OsStr;
+use std::io::Write;
+use std::path::PathBuf;
+
+mod cmd;
+
+const VERSION: &str = concat!("v", crate_version!());
+
+fn main() {
+    init_logger();
+
+    let command = create_clap_command();
+
+    // Check which subcommand the user ran...
+    let res = match command.get_matches().subcommand() {
+        Some(("init", sub_matches)) => cmd::init::execute(sub_matches),
+        Some(("build", sub_matches)) => cmd::build::execute(sub_matches),
+        Some(("clean", sub_matches)) => cmd::clean::execute(sub_matches),
+        #[cfg(feature = "watch")]
+        Some(("watch", sub_matches)) => cmd::watch::execute(sub_matches),
+        #[cfg(feature = "serve")]
+        Some(("serve", sub_matches)) => cmd::serve::execute(sub_matches),
+        Some(("test", sub_matches)) => cmd::test::execute(sub_matches),
+        Some(("completions", sub_matches)) => (|| {
+            let shell = sub_matches
+                .get_one::<Shell>("shell")
+                .ok_or_else(|| anyhow!("Shell name missing."))?;
+
+            let mut complete_app = create_clap_command();
+            clap_complete::generate(
+                *shell,
+                &mut complete_app,
+                "mdbook",
+                &mut std::io::stdout().lock(),
+            );
+            Ok(())
+        })(),
+        _ => unreachable!(),
+    };
+
+    if let Err(e) = res {
+        utils::log_backtrace(&e);
+
+        std::process::exit(101);
+    }
+}
+
+/// Create a list of valid arguments and sub-commands
+fn create_clap_command() -> Command {
+    let app = Command::new(crate_name!())
+        .about(crate_description!())
+        .author("Mathieu David <mathieudavid@mathieudavid.org>")
+        .version(VERSION)
+        .propagate_version(true)
+        .arg_required_else_help(true)
+        .after_help(
+            "For more information about a specific command, try `mdbook <command> --help`\n\
+             The source code for mdBook is available at: https://github.com/rust-lang/mdBook",
+        )
+        .subcommand(cmd::init::make_subcommand())
+        .subcommand(cmd::build::make_subcommand())
+        .subcommand(cmd::test::make_subcommand())
+        .subcommand(cmd::clean::make_subcommand())
+        .subcommand(
+            Command::new("completions")
+                .about("Generate shell completions for your shell to stdout")
+                .arg(
+                    Arg::new("shell")
+                        .value_parser(clap::value_parser!(Shell))
+                        .help("the shell to generate completions for")
+                        .value_name("SHELL")
+                        .required(true),
+                ),
+        );
+
+    #[cfg(feature = "watch")]
+    let app = app.subcommand(cmd::watch::make_subcommand());
+    #[cfg(feature = "serve")]
+    let app = app.subcommand(cmd::serve::make_subcommand());
+
+    app
+}
+
+fn init_logger() {
+    let mut builder = Builder::new();
+
+    builder.format(|formatter, record| {
+        writeln!(
+            formatter,
+            "{} [{}] ({}): {}",
+            Local::now().format("%Y-%m-%d %H:%M:%S"),
+            record.level(),
+            record.target(),
+            record.args()
+        )
+    });
+
+    if let Ok(var) = env::var("RUST_LOG") {
+        builder.parse_filters(&var);
+    } else {
+        // if no RUST_LOG provided, default to logging at the Info level
+        builder.filter(None, LevelFilter::Info);
+        // Filter extraneous html5ever not-implemented messages
+        builder.filter(Some("html5ever"), LevelFilter::Error);
+    }
+
+    builder.init();
+}
+
+fn get_book_dir(args: &ArgMatches) -> PathBuf {
+    if let Some(p) = args.get_one::<PathBuf>("dir") {
+        // Check if path is relative from current dir, or absolute...
+        if p.is_relative() {
+            env::current_dir().unwrap().join(p)
+        } else {
+            p.to_path_buf()
+        }
+    } else {
+        env::current_dir().expect("Unable to determine the current directory")
+    }
+}
+
+fn open<P: AsRef<OsStr>>(path: P) {
+    info!("Opening web browser");
+    if let Err(e) = opener::open(path) {
+        error!("Error opening web browser: {}", e);
+    }
+}
+
+#[test]
+fn verify_app() {
+    create_clap_command().debug_assert();
+}

src/parse/mod.rs

@@ -1,3 +0,0 @@
-pub use self::summary::construct_bookitems;
-
-pub mod summary;

src/parse/summary.rs

@@ -1,216 +0,0 @@
-use std::path::PathBuf;
-use std::fs::File;
-use std::io::{Read, Result, Error, ErrorKind};
-use book::bookitem::{BookItem, Chapter};
-
-pub fn construct_bookitems(path: &PathBuf) -> Result<Vec<BookItem>> {
-    debug!("[fn]: construct_bookitems");
-    let mut summary = String::new();
-    try!(try!(File::open(path)).read_to_string(&mut summary));
-
-    debug!("[*]: Parse SUMMARY.md");
-    let top_items = try!(parse_level(&mut summary.split('\n').collect(), 0, vec![0]));
-    debug!("[*]: Done parsing SUMMARY.md");
-    Ok(top_items)
-}
-
-fn parse_level(summary: &mut Vec<&str>, current_level: i32, mut section: Vec<i32>) -> Result<Vec<BookItem>> {
-    debug!("[fn]: parse_level");
-    let mut items: Vec<BookItem> = vec![];
-
-    // Construct the book recursively
-    while !summary.is_empty() {
-        let item: BookItem;
-        // Indentation level of the line to parse
-        let level = try!(level(summary[0], 4));
-
-        // if level < current_level we remove the last digit of section, exit the current function,
-        // and return the parsed level to the calling function.
-        if level < current_level { break }
-
-        // if level > current_level we call ourselves to go one level deeper
-        if level > current_level {
-            // Level can not be root level !!
-            // Add a sub-number to section
-            section.push(0);
-            let last = items.pop().expect("There should be at least one item since this can't be the root level");
-
-            item = if let BookItem::Chapter(ref s, ref ch) = last {
-                let mut ch = ch.clone();
-                ch.sub_items = try!(parse_level(summary, level, section.clone()));
-                items.push(BookItem::Chapter(s.clone(), ch));
-
-                // Remove the last number from the section, because we got back to our level..
-                section.pop();
-                continue
-            } else {
-                return Err(Error::new( ErrorKind::Other, format!(
-                        "Your summary.md is messed up\n\n
-                        Prefix, Suffix and Spacer elements can only exist on the root level.\n
-                        Prefix elements can only exist before any chapter and there can be no chapters after suffix elements."
-                        )))
-            };
-
-        } else {
-            // level and current_level are the same, parse the line
-            item = if let Some(parsed_item) = parse_line(summary[0]) {
-
-                // Eliminate possible errors and set section to -1 after suffix
-                match parsed_item {
-                    // error if level != 0 and BookItem is != Chapter
-                    BookItem::Affix(_) | BookItem::Spacer if level > 0 => {
-                        return Err(Error::new( ErrorKind::Other, format!(
-                                "Your summary.md is messed up\n\n
-                                Prefix, Suffix and Spacer elements can only exist on the root level.\n
-                                Prefix elements can only exist before any chapter and there can be no chapters after suffix elements."
-                                )))
-                    },
-
-                    // error if BookItem == Chapter and section == -1
-                    BookItem::Chapter(_, _) if section[0] == -1 => {
-                        return Err(Error::new( ErrorKind::Other, format!(
-                                "Your summary.md is messed up\n\n
-                                Prefix, Suffix and Spacer elements can only exist on the root level.\n
-                                Prefix elements can only exist before any chapter and there can be no chapters after suffix elements."
-                                )))
-                    },
-
-                    // Set section = -1 after suffix
-                    BookItem::Affix(_) if section[0] > 0 => {
-                        section[0] = -1;
-                    }
-
-                    _ => {},
-                }
-
-                match parsed_item {
-                    BookItem::Chapter(_, ch) => {
-                        // Increment section
-                        let len = section.len() -1;
-                        section[len] += 1;
-                        let s = section.iter().fold("".to_owned(), |s, i| s + &i.to_string() + ".");
-                        BookItem::Chapter(s, ch)
-                    }
-                    _ => parsed_item
-                }
-
-            } else {
-                // If parse_line does not return Some(_) continue...
-                summary.remove(0);
-                continue;
-            };
-        }
-
-        summary.remove(0);
-        items.push(item)
-    }
-    debug!("[*]: Level: {:?}", items);
-    Ok(items)
-}
-
-
-fn level(line: &str, spaces_in_tab: i32) -> Result<i32> {
-    debug!("[fn]: level");
-    let mut spaces = 0;
-    let mut level = 0;
-
-    for ch in line.chars() {
-        match ch {
-            ' ' => spaces += 1,
-            '\t' => level += 1,
-            _ => break,
-        }
-        if spaces >= spaces_in_tab {
-            level += 1;
-            spaces = 0;
-        }
-    }
-
-    // If there are spaces left, there is an indentation error
-    if spaces > 0 {
-        debug!("[SUMMARY.md]:");
-        debug!("\t[line]: {}", line);
-        debug!("[*]: There is an indentation error on this line. Indentation should be {} spaces", spaces_in_tab);
-        return Err(Error::new(
-            ErrorKind::Other,
-            format!("Indentation error on line:\n\n{}", line)
-            )
-        )
-    }
-
-    Ok(level)
-}
-
-
-fn parse_line(l: &str) -> Option<BookItem> {
-    debug!("[fn]: parse_line");
-
-    // Remove leading and trailing spaces or tabs
-    let line = l.trim_matches(|c: char| { c == ' ' || c == '\t' });
-
-    // Spacers are "------"
-    if line.starts_with("--") {
-        debug!("[*]: Line is spacer");
-        return Some(BookItem::Spacer)
-    }
-
-    if let Some(c) = line.chars().nth(0) {
-        match c {
-            // List item
-            '-' | '*' => {
-                debug!("[*]: Line is list element");
-
-                if let Some((name, path)) = read_link(line) {
-                    return Some(BookItem::Chapter("0".to_owned(), Chapter::new(name, path)))
-                } else { return None }
-            },
-            // Non-list element
-            '[' => {
-                debug!("[*]: Line is a link element");
-
-                if let Some((name, path)) = read_link(line) {
-                    return Some(BookItem::Affix(Chapter::new(name, path)))
-                } else { return None }
-            }
-            _ => {}
-        }
-    }
-
-    None
-}
-
-fn read_link(line: &str) -> Option<(String, PathBuf)> {
-    let mut start_delimitor;
-    let mut end_delimitor;
-
-    // In the future, support for list item that is not a link
-    // Not sure if I should error on line I can't parse or just ignore them...
-    if let Some(i) = line.find('[') { start_delimitor = i; }
-    else {
-        debug!("[*]: '[' not found, this line is not a link. Ignoring...");
-        return None
-    }
-
-    if let Some(i) = line[start_delimitor..].find("](") {
-        end_delimitor = start_delimitor +i;
-    }
-    else {
-        debug!("[*]: '](' not found, this line is not a link. Ignoring...");
-        return None
-    }
-
-    let name = line[start_delimitor + 1 .. end_delimitor].to_owned();
-
-    start_delimitor = end_delimitor + 1;
-    if let Some(i) = line[start_delimitor..].find(')') {
-        end_delimitor = start_delimitor + i;
-    }
-    else {
-        debug!("[*]: ')' not found, this line is not a link. Ignoring...");
-        return None
-    }
-
-    let path = PathBuf::from(line[start_delimitor + 1 .. end_delimitor].to_owned());
-
-    Some((name, path))
-}

src/preprocess/cmd.rs

@@ -0,0 +1,208 @@
+use super::{Preprocessor, PreprocessorContext};
+use crate::book::Book;
+use crate::errors::*;
+use log::{debug, trace, warn};
+use shlex::Shlex;
+use std::io::{self, Read, Write};
+use std::process::{Child, Command, Stdio};
+
+/// A custom preprocessor which will shell out to a 3rd-party program.
+///
+/// # Preprocessing Protocol
+///
+/// When the `supports_renderer()` method is executed, `CmdPreprocessor` will
+/// execute the shell command `$cmd supports $renderer`. If the renderer is
+/// supported, custom preprocessors should exit with a exit code of `0`,
+/// any other exit code be considered as unsupported.
+///
+/// The `run()` method is implemented by passing a `(PreprocessorContext, Book)`
+/// tuple to the spawned command (`$cmd`) as JSON via `stdin`. Preprocessors
+/// should then "return" a processed book by printing it to `stdout` as JSON.
+/// For convenience, the `CmdPreprocessor::parse_input()` function can be used
+/// to parse the input provided by `mdbook`.
+///
+/// Exiting with a non-zero exit code while preprocessing is considered an
+/// error. `stderr` is passed directly through to the user, so it can be used
+/// for logging or emitting warnings if desired.
+///
+/// # Examples
+///
+/// An example preprocessor is available in this project's `examples/`
+/// directory.
+#[derive(Debug, Clone, PartialEq)]
+pub struct CmdPreprocessor {
+    name: String,
+    cmd: String,
+}
+
+impl CmdPreprocessor {
+    /// Create a new `CmdPreprocessor`.
+    pub fn new(name: String, cmd: String) -> CmdPreprocessor {
+        CmdPreprocessor { name, cmd }
+    }
+
+    /// A convenience function custom preprocessors can use to parse the input
+    /// written to `stdin` by a `CmdRenderer`.
+    pub fn parse_input<R: Read>(reader: R) -> Result<(PreprocessorContext, Book)> {
+        serde_json::from_reader(reader).with_context(|| "Unable to parse the input")
+    }
+
+    fn write_input_to_child(&self, child: &mut Child, book: &Book, ctx: &PreprocessorContext) {
+        let stdin = child.stdin.take().expect("Child has stdin");
+
+        if let Err(e) = self.write_input(stdin, book, ctx) {
+            // Looks like the backend hung up before we could finish
+            // sending it the render context. Log the error and keep going
+            warn!("Error writing the RenderContext to the backend, {}", e);
+        }
+    }
+
+    fn write_input<W: Write>(
+        &self,
+        writer: W,
+        book: &Book,
+        ctx: &PreprocessorContext,
+    ) -> Result<()> {
+        serde_json::to_writer(writer, &(ctx, book)).map_err(Into::into)
+    }
+
+    /// The command this `Preprocessor` will invoke.
+    pub fn cmd(&self) -> &str {
+        &self.cmd
+    }
+
+    fn command(&self) -> Result<Command> {
+        let mut words = Shlex::new(&self.cmd);
+        let executable = match words.next() {
+            Some(e) => e,
+            None => bail!("Command string was empty"),
+        };
+
+        let mut cmd = Command::new(executable);
+
+        for arg in words {
+            cmd.arg(arg);
+        }
+
+        Ok(cmd)
+    }
+}
+
+impl Preprocessor for CmdPreprocessor {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book> {
+        let mut cmd = self.command()?;
+
+        let mut child = cmd
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::inherit())
+            .spawn()
+            .with_context(|| {
+                format!(
+                    "Unable to start the \"{}\" preprocessor. Is it installed?",
+                    self.name()
+                )
+            })?;
+
+        self.write_input_to_child(&mut child, &book, ctx);
+
+        let output = child.wait_with_output().with_context(|| {
+            format!(
+                "Error waiting for the \"{}\" preprocessor to complete",
+                self.name
+            )
+        })?;
+
+        trace!("{} exited with output: {:?}", self.cmd, output);
+        ensure!(
+            output.status.success(),
+            format!(
+                "The \"{}\" preprocessor exited unsuccessfully with {} status",
+                self.name, output.status
+            )
+        );
+
+        serde_json::from_slice(&output.stdout).with_context(|| {
+            format!(
+                "Unable to parse the preprocessed book from \"{}\" processor",
+                self.name
+            )
+        })
+    }
+
+    fn supports_renderer(&self, renderer: &str) -> bool {
+        debug!(
+            "Checking if the \"{}\" preprocessor supports \"{}\"",
+            self.name(),
+            renderer
+        );
+
+        let mut cmd = match self.command() {
+            Ok(c) => c,
+            Err(e) => {
+                warn!(
+                    "Unable to create the command for the \"{}\" preprocessor, {}",
+                    self.name(),
+                    e
+                );
+                return false;
+            }
+        };
+
+        let outcome = cmd
+            .arg("supports")
+            .arg(renderer)
+            .stdin(Stdio::null())
+            .stdout(Stdio::inherit())
+            .stderr(Stdio::inherit())
+            .status()
+            .map(|status| status.code() == Some(0));
+
+        if let Err(ref e) = outcome {
+            if e.kind() == io::ErrorKind::NotFound {
+                warn!(
+                    "The command wasn't found, is the \"{}\" preprocessor installed?",
+                    self.name
+                );
+                warn!("\tCommand: {}", self.cmd);
+            }
+        }
+
+        outcome.unwrap_or(false)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::MDBook;
+    use std::path::Path;
+
+    fn guide() -> MDBook {
+        let example = Path::new(env!("CARGO_MANIFEST_DIR")).join("guide");
+        MDBook::load(example).unwrap()
+    }
+
+    #[test]
+    fn round_trip_write_and_parse_input() {
+        let cmd = CmdPreprocessor::new("test".to_string(), "test".to_string());
+        let md = guide();
+        let ctx = PreprocessorContext::new(
+            md.root.clone(),
+            md.config.clone(),
+            "some-renderer".to_string(),
+        );
+
+        let mut buffer = Vec::new();
+        cmd.write_input(&mut buffer, &md.book, &ctx).unwrap();
+
+        let (got_ctx, got_book) = CmdPreprocessor::parse_input(buffer.as_slice()).unwrap();
+
+        assert_eq!(got_book, md.book);
+        assert_eq!(got_ctx, ctx);
+    }
+}

src/preprocess/index.rs

@@ -0,0 +1,105 @@
+use regex::Regex;
+use std::path::Path;
+
+use super::{Preprocessor, PreprocessorContext};
+use crate::book::{Book, BookItem};
+use crate::errors::*;
+use log::warn;
+use once_cell::sync::Lazy;
+
+/// A preprocessor for converting file name `README.md` to `index.md` since
+/// `README.md` is the de facto index file in markdown-based documentation.
+#[derive(Default)]
+pub struct IndexPreprocessor;
+
+impl IndexPreprocessor {
+    pub(crate) const NAME: &'static str = "index";
+
+    /// Create a new `IndexPreprocessor`.
+    pub fn new() -> Self {
+        IndexPreprocessor
+    }
+}
+
+impl Preprocessor for IndexPreprocessor {
+    fn name(&self) -> &str {
+        Self::NAME
+    }
+
+    fn run(&self, ctx: &PreprocessorContext, mut book: Book) -> Result<Book> {
+        let source_dir = ctx.root.join(&ctx.config.book.src);
+        book.for_each_mut(|section: &mut BookItem| {
+            if let BookItem::Chapter(ref mut ch) = *section {
+                if let Some(ref mut path) = ch.path {
+                    if is_readme_file(&path) {
+                        let mut index_md = source_dir.join(path.with_file_name("index.md"));
+                        if index_md.exists() {
+                            warn_readme_name_conflict(&path, &&mut index_md);
+                        }
+
+                        path.set_file_name("index.md");
+                    }
+                }
+            }
+        });
+
+        Ok(book)
+    }
+}
+
+fn warn_readme_name_conflict<P: AsRef<Path>>(readme_path: P, index_path: P) {
+    let file_name = readme_path.as_ref().file_name().unwrap_or_default();
+    let parent_dir = index_path
+        .as_ref()
+        .parent()
+        .unwrap_or_else(|| index_path.as_ref());
+    warn!(
+        "It seems that there are both {:?} and index.md under \"{}\".",
+        file_name,
+        parent_dir.display()
+    );
+    warn!(
+        "mdbook converts {:?} into index.html by default. It may cause",
+        file_name
+    );
+    warn!("unexpected behavior if putting both files under the same directory.");
+    warn!("To solve the warning, try to rearrange the book structure or disable");
+    warn!("\"index\" preprocessor to stop the conversion.");
+}
+
+fn is_readme_file<P: AsRef<Path>>(path: P) -> bool {
+    static RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(?i)^readme$").unwrap());
+
+    RE.is_match(
+        path.as_ref()
+            .file_stem()
+            .and_then(std::ffi::OsStr::to_str)
+            .unwrap_or_default(),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn file_stem_exactly_matches_readme_case_insensitively() {
+        let path = "path/to/Readme.md";
+        assert!(is_readme_file(path));
+
+        let path = "path/to/README.md";
+        assert!(is_readme_file(path));
+
+        let path = "path/to/rEaDmE.md";
+        assert!(is_readme_file(path));
+
+        let path = "path/to/README.markdown";
+        assert!(is_readme_file(path));
+
+        let path = "path/to/README";
+        assert!(is_readme_file(path));
+
+        let path = "path/to/README-README.md";
+        assert!(!is_readme_file(path));
+    }
+}