perf: compile glob patterns to regexp once (Windows-safe retry of #64) #75
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lo1tuma wants to merge 1 commit into
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perf: compile glob patterns to regexp once (Windows-safe retry of #64) #75lo1tuma wants to merge 1 commit into
lo1tuma wants to merge 1 commit into
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shouldInstrument was calling minimatch() per pattern per invocation, which shows up as a hot path in coverage runs over large test suites. Compile each include/exclude/excludeNegated pattern to a RegExp once during construction and reuse them on every shouldInstrument call. The matcher then runs RegExp.prototype.test instead of re-parsing globs. Previous attempt (istanbuljs#64) failed on Windows because minimatch.makeRe produces regexes against forward-slash paths, but Windows paths use backslashes — minimatch() normalized internally, the precompiled regex did not. Normalize backslashes to forward slashes in pathToCheck before testing. Adds a test that drives shouldInstrument with backslash paths so the Windows code path is exercised on every CI run, not only on the Windows job.
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Second attempt at #64. Apologies for the radio silence on the original PR.
shouldInstrumentre-parses every glob viaminimatch()on each call, which shows up as a hot path on large test suites. This compiles each pattern to aRegExponce in the constructor and reuses it.Why this didn't work the first time
minimatch()normalizes backslashes internally;minimatch.makeRe()does not. On Windows,pathToCheckarrives with\separators and never matches he precompiled forward-slash regex, that's what broke the Windows CI on #64.Fix
Normalize
\→/inpathToCheckbefore running the precompiled regex.Test
Added a test that exercises
shouldInstrumentwith backslash paths so the Windows behavior is verified on every CI run, not only on the Windows job.