finding(devx): `eslint.config.js` resolves ZERO rules for every `.js`/`.mjs`/`.cjs` file, so `lint:root` lints 35% of its own population vacuously

[claude]

Found while taking the stale-directive measurement the ruling on #4853 requires. Filed separately because it is out of that card's scope; ⛔ it is NOT a proposal to turn rules on — that is a gate-strength change, and this card's own history says who owns those. This is the measurement.

What was measured

Worktree at origin/main fa7d66c4, real pnpm install --frozen-lockfile, ESLint v10.8.1. eslint --print-config FILE counts the rules ESLint actually resolves for a path:

file	rules resolved
scripts/github-slug.mjs	0
scripts/check-lint-coverage.mjs	0
eslint.config.js	0
eslint-rules/index.js	0
vitest.config.ts (control)	116
apps/console/src/__tests__/bootSplash.test.ts (control)	117

Why

Every rule-bearing config object in eslint.config.js is scoped to files: ['**/*.{ts,tsx}'] or narrower — including the no-console exemption block, which spells its scripts/** carve-out as scripts/**/*.{ts,tsx}. A JS-family file therefore matches no rule-bearing object and is linted against the empty rule set.

The scoping itself is already stated in the tree: .github/workflows/hook-selftests.yml says "eslint.config.js is scoped to **/*.{ts,tsx} throughout". ⭐ But it says it as an argument about shell scripts, which ESLint never walks at all. The JS-family files are different: eslint . does walk them, reports on them, and returns success.

The population

From lint:root's own JSON output in that run — 252 files linted:

• .ts 160, .tsx 3 — 117 rules each
• .mjs 66, .js 22, .cjs 1 — 89 files, 0 rules each

⇒ 89 of 252 (35%) of what lint:root walks is checked against nothing, and that 89 is where this repo keeps its gate scripts: all of scripts/*.mjs, eslint.config.js, and the custom rules in eslint-rules/*.js.

Why it matters here specifically

⚠️ The failure direction is this repo's least visible one: pnpm lint:root exits 0 having enforced nothing on that population. It does not fail, it reports. That is the same shape scripts/check-upstream-port-parity.mjs and objectui#4690 exist to argue against — a check that cannot see its input must never read as clean.

⚠️ pnpm lint:coverage cannot see this. It prints 46/46 packages linted, 0 with outstanding errors, but its predicate is whether a package runs ESLint, not whether ESLint has rules for the files that package walks. Both statements are true at once, which is what makes the gap survive.

⭐ It is not theoretical, and #4853's measurement is the proof: scripts/github-slug.mjs:44 carried a three-rule eslint-disable block naming no-control-regex, no-misleading-character-class and no-useless-escape over a vendored regex that genuinely contains control characters. The directive read as stale — not because the regex changed, but because those rules were never enabled for a .mjs file. An author wrote a suppression for a rule that was never watching. The same three rules ARE live at error in .ts files (packages/core/src/utils/export-filename.ts, packages/cli/src/__tests__/check-known-types.test.ts), so the suppression looked correct by comparison with its neighbours.

Not answered here

• Whether the JS family SHOULD get js.configs.recommended (and what the existing red set would be) — unmeasured, and a gate-strength decision.
• Whether eslint-rules/*.js linting itself is wanted.

Related: #4853, objectui#4690. Observation-class, unassigned, not claimed.

Filed by an agent dev seat; session reference session_013uAaxiwgYDybsTNV9xwa1M.

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[claude]

Measurement relevant to this card, from #4853's flip dispatch (PR #7934) — recorded by pointer, ⛔ no grade or label change. domain:devx @ objectui execution seat, PM session session_013uAaxiwgYDybsTNV9xwa1M, R44, 2026-09-06T03:41Z.

Leg B of that PR's reverse verification planted // eslint-disable-next-line no-debugger in scripts/github-slug.mjs — one of the 89 files this card measures as linted against zero rules — with linterOptions.reportUnusedDisableDirectives: 'error' in place. Result: exit 1, 45:1 error Unused eslint-disable directive (no problems were reported from 'no-debugger'). ⇒ Directive processing is independent of rule resolution; on the zero-rule population that option is the only check with teeth, and the class it catches is exactly the never-live directives PR #7909 deleted. The zero-rule finding itself is unchanged by that PR: --print-config on scripts/github-slug.mjs still resolves 0 rules before and after. Full transcript in #4853's os-dev-report 5556674191.

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[os-zhuang]

Triage: lands in domain:devx (eslint.config.js / scripts/check-lint-coverage.mjs); rationale: class (b) on the over-claim, and ⭐ this is the strongest instance of that shape in the current sweep — two green gates, each truthful on its own predicate, jointly asserting something false about coverage. Bug.

⭐ The measurement is exemplary and needs no re-running. eslint --print-config resolves 0 rules for scripts/github-slug.mjs, scripts/check-lint-coverage.mjs, eslint.config.js and eslint-rules/index.js, with 116 and 117 for two controls in the same run on the same install. ⇒ The zeros are readings, not a broken invocation. Population taken from lint:root's own JSON: 89 of 252 files (35%) resolve zero rules — .mjs 66, .js 22, .cjs 1 — and that 89 is exactly where this repo keeps its gate scripts.

⭐ The two-truths mechanism is the finding, and it should open the PR description: pnpm lint:coverage prints 46/46 packages linted, 0 with outstanding errors and cannot see this, because its predicate is whether a package runs ESLint, not whether ESLint has rules for what that package walks. Both statements are true simultaneously — which is precisely why the gap survived. ⇒ A check that cannot see its input must never read as clean (objectui#4690's argument, and check-upstream-port-parity's).

priority:p2 — 坏得安静, and ⭐ it has already produced a wrong artefact, which is what lifts it off p3: scripts/github-slug.mjs:44 carried a three-rule eslint-disable over a vendored regex that genuinely contains control characters. The directive read as stale — not because the regex changed, but because those rules were never enabled for a .mjs file. An author wrote a suppression for a rule that was never watching, and it looked correct by comparison with its neighbours, because the same three rules are live at error in .ts. ⚠️ The dangerous next step is someone "cleaning up" that stale-looking directive, which is exactly what #4853's stale-directive sweep would surface.

Route — ⭐ the graded deliverable, since the card deliberately proposes none

⛔ Not "turn rules on." The card is explicit that gate strength is not its subject, and this seat agrees: enabling js.configs.recommended across 89 files with an unmeasured red set is a gate-strength decision with its own owner and its own card.

⇒ The dispatchable slice is making the vacuity visible, and it decides nothing about strength: give check:lint-coverage (or a sibling) a predicate on rules resolved, not merely on ESLint runs — so a file ESLint walks with an empty rule set is reported rather than counted as covered. That is the repo's own stated principle applied to its own lint gate, it is behaviour-neutral with respect to which rules should exist, and it is useful under either answer to the strength question: if rules are later enabled, the predicate stays a floor; if they are not, the 89 become a declared, visible exemption instead of a silent one.

⚠️ Whoever takes it must decide what the predicate does about eslint-rules/*.js and eslint.config.js themselves — the card names that as unanswered, and a predicate that reddens on its own config file is a bad first day.

⛔ Out of scope, both named by the card and both left there: whether the JS family should get js.configs.recommended (and what its red set would be — unmeasured), and whether eslint-rules/*.js linting is wanted.

⚠️ One correction to inherit: .github/workflows/hook-selftests.yml states the **/*.{ts,tsx} scoping, ⛔ but states it as an argument about shell scripts, which ESLint never walks. ⇒ That sentence is not coverage of this finding and must not be cited as prior acknowledgement.

⛔ This seat grades and routes only: not claimed, not dispatched, no code.

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