test_runner: exclude BRDA entries for ignored lines in LCOV reporter

[sfgrdsgdsfdrfyg-code]

What

When using /* node:coverage ignore next */ comments to exclude code from coverage, the DA (line coverage) entries are correctly excluded, but BRDA (branch coverage) entries for those same lines remain as uncovered. This causes branch coverage to report incorrect percentages.

Why it matters

Broken branch coverage in CI pipelines that enforce thresholds. Affects anyone using node --experimental-test-coverage with lcov reporter.

How

The lcov.js reporter was not filtering branches on ignored lines. Added a check to skip branches whose line is in the ignored line set.

Closes #61586

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[MoLow]

can you please add / adjust tests?

[codecov]

Codecov Report

❌ Patch coverage is 13.33333% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.66%. Comparing base (d0fa608) to head (0facea0).
⚠️ Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/reporter/lcov.js	13.33%	13 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #62740      +/-   ##
==========================================
- Coverage   89.69%   89.66%   -0.04%     
==========================================
  Files         706      706              
  Lines      218129   218143      +14     
  Branches    41739    41733       -6     
==========================================
- Hits       195649   195592      -57     
- Misses      14411    14463      +52     
- Partials     8069     8088      +19     

Files with missing lines	Coverage Δ
lib/internal/test_runner/reporter/lcov.js	14.04% <13.33%> (-6.52%)	⬇️

... and 51 files with indirect coverage changes

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[sfgrdsgdsfdrfyg-code]

Thanks for the review! I've amended the commit message with PR-URL. I'm looking at the existing lcov test fixture now to understand how to add coverage for the ignore-line BRDA filtering behavior. Will push a test update shortly.

[sfgrdsgdsfdrfyg-code]

Update: Added specific test case for BRDA exclusion on ignored lines.

Added:

• test/test-runner/test-output-lcov-reporter-brda-ignore.mjs - new test case
• test/fixtures/test-runner/output/brda_ignore_output.js - fixture with an ignored branch
• test/fixtures/test-runner/output/lcov_reporter_brda_ignore.js - runner for new fixture
• test/fixtures/test-runner/output/lcov_reporter_brda_ignore.snapshot - expected output (no BRDA for ignored lines)

The test exercises the new filtering logic in lcov.js.

[JakobJingleheimer]

Duplicate of #61598

[sfgrdsgdsfdrfyg-code]

Thanks! You're right - this is a duplicate of #61598 which is already approved and mergeable.

I'll close this PR in favor of #61598. The approach in #61598 (filtering at the coverage.js level) is cleaner than the lcov.js approach I used here.

Thanks @RajeshKumar11 for beating me to it!