The fixtures/{first,}/* pattern returns incorrect results

[mrmlnc]

Environment

• OS Version: macOS 13.1
• Node.js Version: v16.16.0

Actual behavior

{
  entries: [
    'fixtures/first/file.md',
    'fixtures/first/nested'
  ]
}

Expected behavior

The fixtures/{first,}/* can be considered as two patterns:

• fixtures/first/*
• fixtures/*

{
  entries: [
    'fixtures/third',
    'fixtures/second',
    'fixtures/file.md',
    'fixtures/first',
    'fixtures/first/nested',
    'fixtures/first/file.md'
  ]
}

Code sample

const incorrect = fg.sync(['fixtures/{first,}/*'], {
	onlyFiles: false,
});

const correct = fg.sync(['fixtures/first/*', 'fixtures/*'], {
	onlyFiles: false,
});

console.dir({ incorrect, correct }, { colors: true, compact: false, depth: null });

[mrmlnc]

The micromatch package generates the following regexp: ^(?:fixtures\/(first|)\/(?!\.)(?=.)[^/]*?\/?)$.This expression does not match the fixtures/file.md path.

// After expand brace expressions
[
  'fixtures/first/*',
  'fixtures//*' // incorrect
]
[
  /^(?:fixtures\/first\/(?!\.)(?=.)[^/]*?\/?)$/,
  /^(?:fixtures\/\/(?!\.)(?=.)[^/]*?\/?)$/
]

// fixtures/* (correct)
^(?:fixtures\/(?!\.)(?=.)[^/]*?\/?)$

Hm. From my point of view, micromatch generates a knowingly incorrect pattern. However, he did what he had to do - it expands the pattern without any additional processing.

[mrmlnc]

Already fixed in the master by #395 in this package. Will be shipped with 3.3.0.