[newhoggy]

Closes #134

The existing Coverage job runs the last release, so it cannot catch regressions in the PR's own diff, parser or renderer. This adds a parallel advisory Coverage (PR build) job that checks out the immutable PR head, builds its locked debug binary, measures the same checkout with cargo-llvm-cov and invokes ./target/debug/patchcov explicitly for rendering and gating.

The job publishes a separate sticky comment, run summary and artifact before enforcing 90% patch / 95% overall coverage. Fork PRs skip comments but retain reports and gates. It runs only on pull requests and has its own cache key and 15-minute timeout. The existing released-action job and required checks are unchanged.

The new job intentionally has no baseline: it reports patch and total coverage; project deltas and indirect changes remain in the release report. The action always installs a release even in thin mode and has no local-binary input, so direct CLI orchestration avoids changes to the external action. The cost is one extra debug build plus instrumented test run. CONTRIBUTING explains the distinction.

Implementation plan: #134 (comment)

Verification

All passed locally, repeated after fetching/rebasing onto origin/main (which had not moved):

• actionlint .github/workflows/ci.yml and git diff --check.
• cargo fmt --check, cargo test --locked --all-targets, cargo test --locked --doc.
• cargo clippy --locked --all-targets -- -D warnings, cargo run --locked -- lint-markers.
• cargo +1.88.0 test --locked --all-targets and cargo +1.88.0 test --locked --doc.
• RUSTDOCFLAGS='-D warnings' cargo doc --locked --no-deps --document-private-items.
• cargo build --locked --bin patchcov, cargo llvm-cov --locked --all-features --workspace --no-report, and cargo llvm-cov report --lcov --output-path coverage-pr-head.lcov.
• Built CLI markdown render and both gates: 99.4% overall line coverage, no new executable lines in this workflow/docs diff. A deliberate 101% line threshold exits 1 as expected.

Review and limitations

Reviewed the committed changes in ci.yml and CONTRIBUTING.md against origin/main: no actionable findings; none fixed or skipped. No departures from the plan or unrelated follow-ups.

Hosted job execution, actual added CI time and fork-token behavior require GitHub verification; local runs cannot prove comment/artifact publication.

[github-actions]

Coverage

Total: 99.4% ⚪ 0 pp vs main

Comparing 9f564e3..e11c7c9 (merge-base → PR head)

No per-file coverage changes vs main.

Touched files absent from every coverage report (2)

• .github/workflows/ci.yml
• CONTRIBUTING.md

These files may contain no executable code or may have been omitted from the coverage run.

Patch coverage

No new executable lines added by this diff.

_{📦 Full per-file coverage summary · run summary}

[github-actions]

PR build

Measured and rendered by this PR's own patchcov build. No baseline deltas; see the release Coverage report for those.

Coverage

Total: 99.4%

Comparing 9f564e3..e11c7c9 (merge-base → PR head)

No baseline available yet (first run, or the main baseline artifact was missing). Per-file deltas will appear on PRs once a baseline has been published from main.

Touched files absent from every coverage report (2)

• .github/workflows/ci.yml
• CONTRIBUTING.md

These files may contain no executable code or may have been omitted from the coverage run.

Patch coverage

No new executable lines added by this diff.

_{Full per-file summary is attached as the coverage-summary build artifact.}