fix: respect dot option in brace alternatives

[mrmlnc]

Summary

Fix leading-dot handling for direct brace alternatives that begin with a star wildcard (*) or a negated extglob (!(...)) when the brace group starts a path segment.

Previously, these alternatives were not recognized as segment starts because their preceding token is { or , rather than the beginning of the pattern or /. As a result, they could match dotfiles even when dot was disabled.

picomatch.isMatch('.js', '**/{*.js,x}', { dot: false });
// before: true
// after:  false

picomatch.isMatch('.mts', '**/{x,!(*.d).mts}', { dot: false });
// before: true
// after:  false

This fixes the pattern reported in mrmlnc/fast-glob#405:

**/{!(*.d).mts,!(*.d).cts,*.{mjs,cjs,js}}

Implementation

When parsing an ordinary * or !(...), use the existing brace stack and token chain to determine whether the token belongs to a direct brace alternative at the beginning of a path segment.

This allows the parser to:

• handle both the first and subsequent brace alternatives;
• apply the rule only when the brace group itself starts a path segment;
• ignore commas owned by nested extglobs;
• preserve mid-segment and literal-brace behavior;
• distinguish an ordinary * from the *(...) extglob;
• preserve zero-length *(...) matches;
• preserve bash, dot, and noextglob behavior.

No additional parser metadata is introduced.

Scope

This change handles direct, flat brace alternatives only.

Nested-brace alternatives such as {a,{*.js,b}} remain outside its scope. Supporting them requires propagating path-segment context through enclosing brace groups. An alternative implementation covering that case is available in micromatch/picomatch#193.

Refs

mrmlnc/fast-glob#405

[github-code-quality]

Code Coverage Overview

Languages: JavaScript

JavaScript / code-coverage/nyc

The overall line coverage in commit 6b3bc3e in the fg-405 branch is 96%. Line coverage data for the master branch is not yet available.

Show a line coverage summary of the most covered files.

File	master	fg-405 6b3bc3e	+/-
lib/constants.js	—	100%	—
index.js	—	100%	—
posix.js	—	100%	—
lib/scan.js	—	99%	—
lib/parse.js	—	95%	—
lib/picomatch.js	—	95%	—
lib/utils.js	—	90%	—

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_{Updated August 25, 2026 10:03 UTC}