test(coverage): rename-only hunks owe no changed-line coverage

[thymikee]

Summary

The changed-line coverage gate joins lcov with git diff --unified=0 base...HEAD. Rename detection depended on the host's diff.renames: with it off, a pure move became delete + add and owed coverage on every moved line.

• run.ts passes --find-renames=90%: a 100%-similarity move owes nothing; an edited move owes only the hunks that differ from its source; below 90% it is an add. Threshold unchanged (70).
• model.test.ts: fixture diff with a 100% rename, a 90% rename with 3 edited lines, and an ordinary modified file, asserted through parseUnifiedDiff + computeChangedCoverage.
• run.test.ts: git mv under diff.renames=false reports 0/0 (n/a) PASS.
• AGENTS.md: "Pure moves carry their tests unchanged; rename-only hunks owe no new coverage." The session.ts over-budget rule is restored per review; three redundant sentences are compressed to hold the byte budget (9,994/10,000).

Validation

• pnpm check:coverage-changed:test 22/22; pnpm check:agent-guidance 4/4; pnpm check:quick green.
• Planted red A (pre-change run.ts): a pure move owes nothing regardless of the host diff.renames setting FAILS.
• Planted red B (hunkless section owes its whole file): rename-only hunks owe no changed-line coverage FAILS, actual: 35, expected: 5.
• Model test is green pre-change: the defect was the git invocation.
• AGENTS.md-only restoration delta: pnpm check:agent-guidance 4/4 and pnpm check:affected --run pass at cc6c521.
• Full affected gate: green at 4526f80 (pnpm check:affected --run); 32 gates ran: format, lint, typecheck, layering, di-seams, fallow, mcp-metadata, build, package, integration-node, macos-coverage, vitest-related, integration-progress, replay-compat, daemon-wire-compat, affected-selector, gate-manifest(+model), depgraph, tmpdir-leaks(+model), coverage-model, wire-compat-model, production-exports, bundle-owner-files, fixture-cache(+fallback), command-docs, agent-guidance, xctest-selection, maestro-conformance, mutation-model.

Tradeoffs / follow-ups

• No enforcement artifacts changed, so no chore(gates) commit.

[github-actions]

Size Report

Metric	Base	Current	Diff
JS raw	2.58 MB	2.58 MB	0 B
JS gzip	869.6 kB	869.6 kB	0 B
npm bundled raw	2.58 MB	2.58 MB	0 B
npm bundled gzip	869.6 kB	869.6 kB	0 B
npm tarball	1.02 MB	1.02 MB	+10 B
npm unpacked	3.46 MB	3.46 MB	0 B
npm clean-installed	3.46 MB	3.46 MB	0 B

npm unpacked components

Component	Base	Current	Diff
JS / dist source	2.74 MB	2.74 MB	0 B
Apple runner source/project	544.4 kB	544.4 kB	0 B
Apple snapshot presentation source	33.8 kB	33.8 kB	0 B
macOS helper source	54.8 kB	54.8 kB	0 B
Android helper artifacts	43.3 kB	43.3 kB	0 B
Other package files	46.3 kB	46.3 kB	0 B

Startup median (7 runs, lower is better):

Scenario	Base	Current	Diff
CLI --version	31.7 ms	31.1 ms	-0.6 ms
CLI --help	79.9 ms	80.0 ms	+0.2 ms

Top changed chunks: no changes in the largest emitted chunks.

Top changed packed files

No changed packed files.

[thymikee]

BLOCKED at 34bc30af0fa4a76c286cebf7e74ec63c773e8af3.

Owner-action CI failure: Lint & Format is red because oxfmt --check reports scripts/coverage-changed/run.ts as unformatted. Lint itself is clean; this is not infrastructure.

No code finding beyond the required formatting fix: the owning route correctly forces git diff --find-renames=90%, the real temp-repo planted-red proves host diff.renames=false formerly misclassified a pure move, and the model test covers edited rename hunks. All other exact-head checks are green and package size is unchanged.

Do not apply ready-for-human while required CI is red.

[thymikee]

Lint & Format: ran pnpm format repository-wide; scripts/coverage-changed/run.ts reformatted (git diff arg array collapsed to one line), pnpm format:check clean, committed as style: format coverage-changed run.ts. Rebased on main; no conflicts. Focused coverage-changed tests (22/22) and pnpm check:quick pass locally. Head: 4526f80. The full affected gate result follows from the gate stage.

[thymikee]

BLOCKED at 4526f80967059fc332284f6089d2a84579f149b9.

The prior formatting failure is resolved and the rename-coverage implementation/tests are correct.

Required iOS Smoke is now red due to unrelated fixture accessibility-capture truncation (is absent cannot establish close-sheet absence); #2248 changes no iOS/runtime/fixture code, so it appears infrastructure/device evidence, but this exact head needs a passing rerun or baseline control before readiness. No label.

[thymikee]

BLOCKED at 4526f80967059fc332284f6089d2a84579f149b9. The rename implementation/tests and exact-head CI are clean, but the AGENTS.md edit also deletes the unrelated hard rule that src/daemon/handlers/session.ts is over budget and must be extracted before adding behavior. Restore that rule; then no remaining blocker.

[thymikee]

Restored the over-budget rule for src/daemon/handlers/session.ts in AGENTS.md, worded as it stood on main: "already over budget; extract the relevant platform-specific concept before adding behavior." To stay under the 10,000-byte budget (now 9,994), three redundant phrasings elsewhere in the file were tightened without dropping any rule. pnpm check:agent-guidance 4/4 and pnpm check:affected --run pass at cc6c521.

[thymikee]

Code review is clean, but this head is BLOCKED by iOS Smoke. The rename-only coverage logic and regressions are sound, including explicit 90% rename detection and the repository-level diff.renames=false case. The lone failure is the shared assert closed fixture sheet is absent truncated-observation assertion, also seen on #2237 and unrelated to this tooling-only diff. Rerun iOS Smoke; merge only after exact-head green or after the shared lane is separately repaired.

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-09-04 09:58 UTC