test_runner: match coverage globs against cwd-relative paths only

[NAVEENKUMARKR777]

Summary

--test-coverage-exclude and --test-coverage-include — including the built-in default pattern used to drop test files from coverage reports — were matched against both the cwd-relative path and the absolute filesystem path of every candidate file.

For a relative-style glob such as the default **/{test,test/**/*,test-*,*[._-]test}.{js,mjs,cjs}, matching against the absolute path lets a leading ** cross into directory segments that have nothing to do with the project: a container WORKDIR of /test, a home directory literally named test, a CI checkout path with a test segment, and so on. Any project living under such a path had every one of its files spuriously match the default exclude glob and silently vanish from the coverage report, even though --experimental-test-coverage reported 100% coverage of nothing.

This is #58654, open since June 2025 and confirmed by a maintainer. A previous fix attempt (#62362) stalled and auto-closed because it dropped absolute-path matching entirely, which broke the (intentional, if under-justified) ability to pass an absolute --test-coverage-include/--test-coverage-exclude pattern — see the discussion in #53553.

Why this wasn't caught by the existing tests

This repo's own coverage-default-exclusion tests run from test/.tmp.N, i.e. from inside this repository's own test/ directory — which should be exactly the scenario that triggers the bug. It doesn't, purely by coincidence: the absolute-path matcher uses dot: false (added in 22e99dc / #63401, to fix a related-but-different dotfile-matching issue), and the .tmp.N segment is dot-prefixed, which blocks the buggy glob from crossing it. That masked the bug in-repo while leaving it fully reproducible for any real project whose path doesn't happen to contain a dotfile segment between the ancestor test directory and the source files (i.e. almost everyone hitting this in the wild). The new regression test is deliberately set up under a directory outside of test/.tmp.N so it actually exercises the bug — I verified it fails without the fix and passes with it.

Fix

Only match a glob against the absolute path when the glob pattern is itself an absolute path (e.g. an explicit /abs/path/** passed to --test-coverage-include). Every relative-style pattern, including all of the built-in default exclude patterns, is now evaluated exclusively against each file's path relative to the current working directory, which is what those patterns were actually designed to describe. This keeps the ability to use an absolute include/exclude pattern intact while eliminating the accidental ancestor-path leak.

doc/api/cli.md is updated to describe the corrected matching semantics.

Test plan

• Reproduced the bug against a from-scratch build, confirmed the fix resolves it
• Temporarily reverted just the lib/internal/test_runner/coverage.js change and confirmed the new regression test fails (proving it actually catches the bug), then restored the fix and confirmed it passes
• python3 tools/test.py parallel/test-runner-coverage-default-exclusion parallel/test-runner-coverage parallel/test-runner-coverage-thresholds parallel/test-runner-coverage-source-map parallel/test-runner-run-coverage parallel/test-config-file parallel/test-runner-flag-propagation — all pass
• Full test-runner parallel suite (83 files) and test-runner output-snapshot suite (109 files) — all pass, no regressions
• Confirmed the dotfile-exclusion behavior from Default behavior of --test-coverage-exclude globbing does NOT apply to "dotfiles" like .mytest.cjs (common globbing oversight) #63397/test_runner: match dotfiles in default coverage exclude #63401 still works correctly
• eslint clean on all changed files

Fixes: #58654

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[github-actions]

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[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.18%. Comparing base (fd6682c) to head (e16e12e).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/coverage.js	80.00%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65940      +/-   ##
==========================================
+ Coverage   90.16%   90.18%   +0.01%     
==========================================
  Files         771      771              
  Lines      265445   265454       +9     
  Branches    50455    50463       +8     
==========================================
+ Hits       239329   239389      +60     
+ Misses      17056    17002      -54     
- Partials     9060     9063       +3     

Files with missing lines	Coverage Δ
lib/internal/test_runner/coverage.js	60.39% <80.00%> (+0.06%)	⬆️

... and 34 files with indirect coverage changes

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[MikeMcC399]

This PR is failing linting tests. See the comments in the tests for more detail.

See also Pull requests > Step 6: Test with further details in the linked document section BUILDING > Running tests.

To run the linter, use make lint / vcbuild lint. It will lint JavaScript, C++, and Markdown files.

[NAVEENKUMARKR777]

Thanks for flagging — the `lint-js-and-md` failure was `doc/node.1` being out of date after the `doc/api/cli.md` wording change (the man page is generated from the markdown and checked for staleness in CI). Ran `make node.1` to regenerate it and `make lint-md` locally to confirm it's clean, then amended the commit and force-pushed.

[NAVEENKUMARKR777]

Re the Codecov note: the missing/partial lines were the `isAbsolute(pattern)` branch and both `matcher.absolute?.match(...)` call sites — i.e. the "pattern is itself an absolute path" case, which (worth noting) had no test coverage anywhere in the codebase even before this PR. Added two tests exercising it directly, for both `--test-coverage-exclude` and `--test-coverage-include` with an absolute pattern, and verified they actually fail if that branch is broken before pushing.