test_runner: match dotfiles in default coverage exclude

[semimikoh]

The default coverage exclude patterns ... (본문)

Fixes: #63397

Problem

node --experimental-test-coverage includes dotfile test files (e.g. test/.foo.cjs) in the coverage report even though the default exclude patterns are intended to drop everything under test/. Non-dotfile siblings are correctly excluded.

This is caused by matchGlobPattern calling minimatch without dot: true; minimatch's default behavior is to not match dot-prefixed entries unless the pattern itself starts with a dot.

Reported in #63397.

Fix

• lib/internal/fs/glob.js: extend matchGlobPattern with an optional options argument forwarded to minimatch. Fixed options (nocase, windowsPathsNoEscape, etc.) still take precedence so callers cannot accidentally override them.
• lib/internal/test_runner/coverage.js: route the four exclude/include match calls through a small helper that passes { dot: true }. Applied to both exclude and include for consistency.

Test

Added a new scenario to test-runner-coverage-default-exclusion.mjs that runs test/.dotfile.cjs explicitly and asserts the dotfile does not appear in the coverage report under the default exclude patterns. The new fixture test/.dotfile.cjs exercises the same logic-file.js as the existing fixtures.

Fixes: #63397

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

❌ Patch coverage is 95.23810% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 90.25%. Comparing base (0032189) to head (8437db0).
⚠️ Report is 616 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/coverage.js	95.23%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #63401      +/-   ##
==========================================
+ Coverage   90.23%   90.25%   +0.02%     
==========================================
  Files         741      741              
  Lines      241194   241210      +16     
  Branches    45432    45430       -2     
==========================================
+ Hits       217640   217704      +64     
+ Misses      15129    15080      -49     
- Partials     8425     8426       +1     

Files with missing lines	Coverage Δ
lib/internal/test_runner/coverage.js	63.26% <95.23%> (+0.73%)	⬆️

... and 27 files with indirect coverage changes

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[mcollina]

@avivkeller PTAL

[mcollina]

lgtm

[mcollina]

lgtm

[avivkeller]

Can't we pass the same options and thus and use the same matcher for both or no?

[semimikoh]

Intentional — relative needs dot: true so the default exclude globs match project dotfiles like test/.foo.test.js (the point of this PR), but absolute deliberately leaves it off. Enabling dot: true there could make a glob unintentionally match a dot segment that shows up in the absolute path for unrelated reasons (e.g. an OS temp dir like test/.tmp.0), which isn't something the user's pattern was written to target.

[avivkeller]

Shouldn't they be on par? As in, if we are changing this to include dots locally, wouldn't it make sense to also include them globally?

[semimikoh]

Not quite symmetric on purpose — I actually tested this by flipping absolute to use dot: true too and running it against the exact test/**/* default pattern.

Node's own test runner puts NODE_TEST_TMPDIR under a dot-prefixed directory (test/.tmp.<n>/, see test/common/tmpdir.js). With dot: true on absolute, ** is allowed to traverse into .tmp.<n>, so the default test/**/* exclude pattern ends up matching the absolute path of any file running under that tmp dir — e.g. .../test/.tmp.0/logic-file.js matches test/**/*.js, even though logic-file.js is a normal source file that should stay covered.

absolute (dot:false, current) match: false   // logic-file.js correctly stays covered
absolute (dot:true)          match: true    // logic-file.js gets wrongly excluded

Since basically every Node test that uses a tmpdir runs under test/.tmp.N/, making absolute symmetric with dot: true would cause widespread false-exclusions whenever coverage runs inside the Node source tree itself. relative only needs dot: true for * to match a leading dot in the basename (e.g. .foo.test.js); it doesn't need ** to traverse arbitrary dot directories the way absolute would.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/76254/