Files
compiler-explorer/test/sources/builtin-tests.ts
Matt Godbolt (bot acct) 6774d762ce Construct builtin examples source explicitly at startup (#8828)
Follow-up to #8779 (which fixed #8601, `builtin.sourcePath` being
ignored). Two related changes:

### 1. Construct the builtin source explicitly at startup (restore
fail-fast)

#8779 made the builtin "Examples" source read its config lazily, on the
first `list()`/`load()`. That fixed correctness but moved the failure
mode: a misconfigured `sourcePath` (missing/unreadable dir) no longer
fails at startup. The server boots, passes healthchecks, takes traffic,
and then throws on the first request that opens Examples.

This restores fail-fast by constructing the source explicitly once
configuration is loaded:

- Replace the `builtin` module-level singleton with a `BuiltinSource`
class whose constructor scans the examples directory, plus a
`createBuiltinSource()` factory that reads `builtin.sourcePath`.
- `lib/sources/index.ts` exposes `createSources()` instead of a
top-level `sources` array (a top-level array would re-run config reads
at import time, reintroducing #8601).
- `initialiseApplication` constructs the sources after config load and
passes the `Source[]` to `ClientOptionsHandler` and
`setupControllersAndHandlers` (both already accept injected sources).

A bad `sourcePath` now throws during startup, before the instance
reports healthy. The lazy fix's correctness (config read after
`initialize()`) is preserved.

### 2. Single source of truth for the examples path

`GolangParser` independently re-read `('builtin', 'sourcePath',
'./examples/')` to locate `go/default.go`, duplicating where the
examples directory is defined. Export `getExamplesRoot()` from
`lib/sources/builtin.ts` and use it in both `createBuiltinSource()` and
`GolangParser`, so the config key and default live in one place.
Behaviour is unchanged (same value resolved); it removes the drift risk
if the key or default ever changes.

### Tests
Tests construct `BuiltinSource` directly with a fixture directory (no
import-order/`resetModules` dance), cover the unknown-example path,
assert fail-fast on a non-existent dir, and verify
`createBuiltinSource()` reads the configured path.

- `npx vitest --run test/sources/builtin-tests.ts
test/compilers/argument-parsers-tests.ts`
- `npm run ts-check`
- `npm run lint-check`

---------

Co-authored-by: mattgodbolt-molty <mattgodbolt-molty@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-14 22:38:23 +01:00

111 lines
5.0 KiB
TypeScript

// Copyright (c) 2026, Compiler Explorer Authors
// All rights reserved.
//
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//
// * Redistributions of source code must retain the above copyright notice,
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
import fs from 'node:fs/promises';
import os from 'node:os';
import path from 'node:path';
import {afterEach, describe, expect, it} from 'vitest';
import * as props from '../../lib/properties.js';
import {BuiltinSource, createBuiltinSource} from '../../lib/sources/builtin.js';
const tempDirs: string[] = [];
async function makeTempDir() {
const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'ce-builtin-sources-'));
tempDirs.push(tempDir);
return tempDir;
}
async function makeExamplesDir(source: string) {
const examplesPath = path.join(await makeTempDir(), 'custom-examples');
const languagePath = path.join(examplesPath, 'customlang');
await fs.mkdir(languagePath, {recursive: true});
await fs.writeFile(path.join(languagePath, 'configured_example.cpp'), source);
return examplesPath;
}
afterEach(async () => {
props.reset();
await Promise.all(tempDirs.splice(0).map(tempDir => fs.rm(tempDir, {recursive: true, force: true})));
});
describe('BuiltinSource', () => {
it('lists and loads examples from the given directory', async () => {
const source = 'int configured_example() { return 42; }\n';
const builtin = new BuiltinSource(await makeExamplesDir(source));
await expect(builtin.list()).resolves.toEqual([
{lang: 'customlang', name: 'configured example', file: 'configured_example'},
]);
await expect(builtin.load('customlang', 'configured_example')).resolves.toEqual({file: source});
});
it('returns "No path found" for an unknown example', async () => {
const builtin = new BuiltinSource(await makeExamplesDir('int x;\n'));
await expect(builtin.load('customlang', 'nope')).resolves.toEqual({file: 'No path found'});
});
it('returns "Could not read file" when a listed example becomes unreadable', async () => {
const examplesPath = await makeExamplesDir('int x;\n');
const builtin = new BuiltinSource(examplesPath);
await fs.rm(examplesPath, {recursive: true, force: true});
await expect(builtin.load('customlang', 'configured_example')).resolves.toEqual({file: 'Could not read file'});
});
it('fails fast when constructed with a non-existent sourcePath', async () => {
const missingPath = path.join(await makeTempDir(), 'does-not-exist');
expect(() => new BuiltinSource(missingPath)).toThrow();
});
});
describe('createBuiltinSource', () => {
it('reads sourcePath from properties at construction time', async () => {
const source = 'int configured_example() { return 42; }\n';
const examplesPath = await makeExamplesDir(source);
const configPath = path.join(await makeTempDir(), 'config');
await fs.mkdir(configPath, {recursive: true});
await fs.writeFile(path.join(configPath, 'builtin.test.properties'), `sourcePath=${examplesPath}\n`);
props.initialize(configPath, ['test']);
const builtin = createBuiltinSource();
await expect(builtin.list()).resolves.toEqual([
{lang: 'customlang', name: 'configured example', file: 'configured_example'},
]);
});
it('throws with builtin.sourcePath context when the configured dir is missing', async () => {
const missingPath = path.join(await makeTempDir(), 'does-not-exist');
const configPath = path.join(await makeTempDir(), 'config');
await fs.mkdir(configPath, {recursive: true});
await fs.writeFile(path.join(configPath, 'builtin.test.properties'), `sourcePath=${missingPath}\n`);
props.initialize(configPath, ['test']);
expect(() => createBuiltinSource()).toThrow(/builtin\.sourcePath/);
});
});