0013. Exclude globs stay on picomatch

Status: Accepted (2026-09-30), from the second Phase 0 check of the refactor plan (§2.7, §8.4).

Context

The index leaves out what files.exclude, search.exclude, and deckard.exclude name. createExcludeMatcher reads those settings the way VS Code reads files.exclude: it hands the patterns to picomatch with { dot: true }, since VS Code’s * matches names that start with a dot, and tries every prefix of a path, so a pattern that names a folder also leaves out what is inside it. ParkingService (src/services/parkingService.ts) uses the same matcher.

picomatch is one package, inlined into dist/extension.js. The plan’s goal is a host bundle with no third-party code (§2.7), and Node has shipped path.matchesGlob since 22.5. It takes no options, so the plan made the swap depend on a check: the swap happens only if path.matchesGlob on the extension host’s Node agrees with picomatch on every exclude pattern the tests hold.

The check

The comparison ran the matcher’s prefix rule both ways, once with picomatch(patterns, { dot: true }) and once with path.matchesGlob (and path.posix.matchesGlob), over the 11 pattern and path pairs in src/test/workspace.test.ts and src/test/exclude-folders.test.ts. It ran inside the extension host of VS Code 1.139.1 (Node 24.20.0), where no experimental warning was raised, and again on Node 26.8.1.

The other eight pairs agree. The three that disagree have two causes:

• Names that start with a dot. path.matchesGlob never lets * or ** match a name that starts with a dot, and it takes no option to change that. VS Code does let them, which is why the scanner passes { dot: true }.
• Escaped brackets. Deckard’s Exclude from Deckard command writes a folder named [draft] as the key notes/\[draft\], so the brackets are literal. Node’s matcher treats a backslash as a path separator, not an escape, on every platform, so the key no longer names the folder.

Ten more patterns taken from VS Code’s defaults and common shapes, such as **/.git, **/{node_modules,.git}, and **/[Dd]rafts, agreed on the 13 paths tried. They were informational; the tests decide.

Decision

picomatch stays. It is the one third-party package left in the extension host after Phase 6, and the plan’s Phase 1 drops the swap.

Consequences

• The host bundle ships one third-party package, picomatch, which has no dependencies of its own. Decision 0011 holds with that one exception.
• The exclude tests keep pinning the two behaviors Node lacks, so a later attempt to swap would fail them rather than change which notes are indexed.
• Writing Deckard’s own glob matcher was not considered worth it. It would have to reproduce VS Code’s glob dialect, braces and classes included, and that is more code to own than one small, dependency-free package.

Alternatives considered

• path.matchesGlob with the dot rule worked around, for example by trying each pattern again with every * rewritten. That is a second glob dialect to maintain, and it does not fix the escaped brackets.
• VS Code’s RelativePattern and workspace.findFiles. They match files on disk, not a path the scanner already holds, and would tie the pure matcher to vscode.