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Michał Pierzchała 423927fdd8 chore(mutation): shrink to report-only — drop the ratchet, baseline and graduation (#1457, #1781) (#1828)
* chore(mutation): shrink the lane to report-only (#1457, #1781 wave 2)

The mutation harness's two real catches (#1474, #1475) both came from humans
reading the weekly score report. The ratchet half never operated: the baseline
was committed exactly twice (8cce0ef6b, 60400d04b), both times with
`stableRuns: 0, gating: false`, and was never updated after the very fixes it
triggered — the weekly job computed a new baseline and then `git checkout --`d
it, uploading a proposal nobody applied in 3+ weeks. A gate nobody arms is
harness weight; the report is the part that paid.

Deletes ratchet.ts + ratchet.test.ts, mutation-baselines/, and every
baseline/graduation/gating path in run.ts (`--update`, `mutation:baseline`).
run.ts now exits non-zero only on a harness failure, never on a score. The
report renders the per-kernel table (kernel, score, killed, survived, total,
timeouts) plus the surviving mutants a strengthening PR works from.

Kernel scoping stays: stryker.config.json and KERNEL_MODULES are untouched.

* fix(mutation): restore denominator coverage and publish the table before judging the shard set

Review of #1828:
- `report.test.ts` re-asserts that Ignored/CompileError/RuntimeError leave the
  denominator — the one behaviour `ratchet.test.ts` covered and nothing replaced.
  A `tally()` edit that counted tool noise would have deflated every published
  score with a green `mutation:test`.
- `assertShardsCoverModules` now runs after `emit()`, so an incomplete shard set
  still publishes the kernels that completed instead of only an error string.
  This makes the workflow comments' claim about the job summary true rather than
  re-wording them down.

* chore(mutation): trigger the affected lane on exactly the paths that can select mutants

The PR lane returns an empty matrix unless the diff touches the harness, so the
kernel-source and `**/*.test.ts` triggers only bought a 1-4 min no-op job on
~96% of PRs. `on.pull_request.paths` is now exactly `LANE_TOOLING` plus the
workflow file, asserted in both directions by workflow.test.ts against the
exported constant — a missing path would let a harness change merge unproven,
an extra one starts a job that can only answer `[]`.

Also drops the workflow header's contradictory scope paragraph: it claimed the
lane selects on kernel sources and any test reaching one, which has not been
true since the ratchet went.

* fix(mutation): score and publish a short shard set before failing on the count

The expected-count check ran inside readShardedReports, before anything was
summarized, so on the weekly's real `--expect-shards 10` one dead shard threw
away the nine that had reported — the earlier reorder only moved the
zero-mutants check. The merge now returns the shard count, and both verdicts
run after emit() with the same exit code and `score` stage.

Regression uses the weekly argument shape (`--expect-shards 10`, one shard
present) and asserts the reporting kernel's row reaches stdout while the run
still fails.
2026-08-18 17:47:29 +02:00

82 lines
3.4 KiB
TypeScript

// The workflows' YAML cannot read the kernel registry or the lane's own source
// list, so these assertions keep them in step: a module added to KERNEL_MODULES
// that no weekly shard runs would silently drop out of the sweep, and a PR path
// filter out of step with LANE_TOOLING either lets a harness change merge
// unproven or starts a job that selects nothing.
import assert from 'node:assert/strict';
import fs from 'node:fs';
import path from 'node:path';
import { test } from 'node:test';
import { shardMatrix } from './modules.ts';
import { LANE_TOOLING } from './run.ts';
const repoRoot = path.resolve(import.meta.dirname, '../..');
function workflow(name: string): string {
return fs.readFileSync(path.join(repoRoot, '.github/workflows', name), 'utf8');
}
test('the weekly sweep shards exactly the registry matrix', () => {
const yaml = workflow('mutation-weekly.yml');
const jobs = [...yaml.matchAll(/^ {10}- \{ (?<entry>[^}]+) \}$/gm)].map((match) =>
Object.fromEntries(
match
.groups!.entry.split(', ')
.map((pair) => pair.split(': ') as [string, string])
.map(([key, value]) => [key, value]),
),
);
assert.deepEqual(
jobs,
shardMatrix().map((spec) =>
spec.shard ? { ...spec } : { name: spec.name, module: spec.module },
),
);
});
test('the weekly sweep merges the shards into one score table', () => {
const yaml = workflow('mutation-weekly.yml');
assert.match(yaml, /gate: mutation-check[\s\S]*--report-dir/);
assert.match(yaml, /GITHUB_STEP_SUMMARY|\$GITHUB_STEP_SUMMARY/);
// A dead shard must not be merged into a table that looks like a sweep.
assert.match(
yaml,
new RegExp(`--expect-shards\\s+${shardMatrix().length}\\b`),
'the weekly report does not require the full shard set',
);
});
// A shard that outruns the job timeout reports nothing, so the per-shard budget
// is the acceptance criterion made mechanical.
test('no mutation shard is allowed to exceed the 30-minute budget', () => {
for (const name of ['mutation-weekly.yml', 'mutation-affected.yml']) {
for (const [, minutes] of workflow(name).matchAll(/timeout-minutes: (\d+)/g)) {
assert.ok(Number(minutes) <= 30, `${name} declares a ${minutes}-minute job`);
}
}
});
// Only a harness diff can produce a non-empty matrix, so the trigger is asserted
// in both directions against LANE_TOOLING: a missing path lets a harness change
// merge without ever running a mutant, and an extra one starts a select job that
// can only answer `[]`.
test('the affected lane triggers on exactly the lane sources that can select mutants', () => {
// Quote style is the formatter's business (oxfmt formats the workflow tree), so
// accept either spelling of the same scalar rather than pinning this gate to it.
const paths = [
...workflow('mutation-affected.yml').matchAll(/^ {6}- (?<q>['"])(?<glob>[^'"]+)\k<q>$/gm),
].map((match) => match.groups!.glob);
const expected = [
...LANE_TOOLING.map((prefix) => (prefix.endsWith('/') ? `${prefix}**` : prefix)),
// The workflow reruns itself so a trigger edit is proven by the lane it edits.
'.github/workflows/mutation-affected.yml',
];
assert.deepEqual(
[...paths].sort(),
[...expected].sort(),
'the PR path filter drifted from LANE_TOOLING in scripts/mutation/run.ts',
);
assert.match(workflow('mutation-affected.yml'), /gate: mutation-affected[\s\S]*--list-affected/);
});