## What & why
We used to enforce the BSD-2-Clause license banner on every source file
via `eslint-plugin-header`. That check was lost when we migrated from
ESLint to Biome (#7033), which has no equivalent rule. This PR
reinstates it as a standalone node script, modelled on the existing
`etc/scripts/check-frontend-imports.js`.
### Why a script rather than a Biome rule
Biome 2.x has no built-in license/header rule and no plugin equivalent
to `eslint-plugin-header`; its experimental GritQL plugins aren't suited
to whole-file-prefix matching. A script needs zero new dependencies and
gives full control over scope and exemptions.
## The check (`etc/scripts/check-license-headers.js`)
A file "has an appropriate banner" if, ignoring an optional shebang, it
opens with a `// Copyright (c) …` line **and** contains the BSD-2-Clause
disclaimer body. The year and copyright holder are intentionally **not**
constrained — the tree legitimately has many holders (Compiler Explorer
Authors, Arm, Microsoft, HRT, individuals). The `(c)`/`(C)` marker is
matched case-insensitively.
**Scope:** `.ts/.js/.mjs/.cjs` under `lib/ static/ shared/ types/ test/
cypress/`.
**Exempt:** generated files (`lib/asm-docs/generated`), vendored
(`docenizer/vendor`), `.d.ts`, and three third-party ports that carry
their own upstream license — `static/ansi-to-html.ts` (MIT),
`lib/node-graceful.ts` (MIT), `shared/rison.ts` (Nanonid/rison port).
**Wired into:** CI (`test-and-deploy.yml`), `npm run check`, the `make
pre-commit` target, the husky pre-commit hook, and `lint-staged` (per
staged file).
Usage:
```
node ./etc/scripts/check-license-headers.js # scan the tracked tree
node ./etc/scripts/check-license-headers.js <files...> # scan specific files (lint-staged)
```
## Backfill
The check surfaced **42 CE-authored files** missing the banner. This PR
backfills them all with the standard `Copyright (c) <year>, Compiler
Explorer Authors` banner, using each file's **git creation year**
(added-at-this-path, so no `--follow` rename artifacts).
## Verification
- `check-license-headers` → clean (was 42 failures)
- `biome check` on all source → no fixes needed (banner format matches
existing convention)
- `tsc` backend + frontend + tests → clean
- pre-commit gauntlet (lint, ts-check, related tests: 528 passed) ran on
commit
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: mattgodbolt-molty <mattgodbolt-molty@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Enable Biome's `organizeImports` with groups matching the original
ESLint `import/order` configuration:
1. **Node builtins** (`node:fs`, `path`, etc.)
2. *(blank line)*
3. **Third-party packages** (`express`, `@sentry/node`, etc.)
4. *(blank line)*
5. **Local/relative imports** (`../foo.js`, `./bar.js`, aliases)
This resolves the inconsistency where Biome wasn't enforcing import
grouping, meaning new files would lose the blank-line separation that
the old ESLint config enforced.
### Impact
- **354 files** updated out of 738 checked (~48%)
- **+188 / -240 lines** (net -52) — almost entirely single blank line
additions/removals between import groups
- No import reordering; purely group separator consistency
Fixes#7373🤖 Generated by LLM (Claude, via OpenClaw)
- latest biome, and fix its configuration
- fixes "static" content to be globally configured too (instead of
per-line)
- fixes issues:
- imports fixed up
- `Date.now()` vs `+new Date()`
- some unused things `_` prefixed
After discussion with the team, turned off the unused parameter warning.
## Summary
- Fixes EBADF error in HeaptrackWrapper by removing redundant file
descriptor close operation
- The net.Socket takes ownership of the FD and closes it during cleanup,
making manual close unnecessary and dangerous
## Root Cause Analysis
The issue occurred in `lib/runtime-tools/heaptrack-wrapper.ts:133` where
the code attempted to manually close a file descriptor that was already
owned by a `net.Socket`. When creating a socket with `new
net.Socket({fd: fd})`, the socket takes ownership of the file descriptor
and closes it during cleanup operations like `resetAndDestroy()`.
Attempting to close the FD again results in:
1. EBADF errors when the FD hasn't been recycled
2. Potentially closing a different resource if the FD has been recycled
by the OS
## Solution
Removed the manual `oldfs.close(fd)` call since the socket handles FD
cleanup automatically. This prevents both the EBADF error and the more
dangerous scenario of closing recycled file descriptors.
## Verification
Created tests to verify that `net.Socket` takes ownership of file
descriptors:
```javascript
// Test confirms that after socket.destroy(), the FD is no longer valid
const fd = fs.openSync(pipePath, O_RDWR | O_NONBLOCK);
const socket = new net.Socket({ fd: fd, readable: true, writable: true });
socket.destroy();
// fs.fstatSync(fd) throws EBADF - confirming FD was closed by socket
```
## Test Plan
- [x] TypeScript compilation passes
- [x] Minimal test suite passes
- [x] Pre-commit hooks pass
- [x] Created unit test to verify net.Socket FD ownership behavior
Fixes COMPILER-EXPLORER-EA7
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
Remove most, if not all, of the synchronous file reads. Hopefully this
will help a little with performance and "event loop lag". Mostly, it's
"try not to use third party packages when builtins now do the work".
Local testing seems OK - but needs a good poke around on staging to
exercise all the paths.
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