CODEOWNERS Validator Companion (VS Code)

Validates a CODEOWNERS file — duplicated patterns, invalid owner syntax, pattern shadowing, unmatched patterns, and files with no owner. No data leaves your editor.

v0.1, new niche. Not a port from the Gap Hunter Labs IntelliJ- family catalog — an original candidate found via a real evidence search: the reference CLI validator mszostok/codeowners-validator's own README states plainly "This tool is not available as a VS Code extension." This extension is an original implementation modeled on that tool's publicly documented check list, not a translation of its source.

What it checks

Duplicated patterns — the same pattern declared twice; only the last one in the file ever takes effect, so the earlier declaration's owners are silently ignored.
Invalid owner syntax — an owner that isn't @username, @org/team, or a valid email address.
Pattern shadowing — CODEOWNERS uses "last matching pattern wins"; a specific earlier pattern whose owners never actually apply because a broader pattern later in the file also matches the same paths (the classic bug: a catch-all block added at the bottom silently overriding everything above it).
Unmatched patterns — a pattern that doesn't match any file currently in the workspace (a typo, or a path that moved).
Files with no owner — files not covered by any pattern, or whose last-matching pattern has no owners.

The last two checks scan the whole workspace, so they run on file open/save, not on every keystroke — the syntax checks above them are instant either way. Skipped entirely on workspaces over 5,000 files (v0.1 scope: avoid a slow or misleading partial scan rather than guess).

v0.1 scope, honestly noted: pattern matching covers the common gitignore-style shapes (/dir/, *.ext, **, a bare name matching anywhere in the tree) — full gitignore semantics (character classes, ! negation) aren't implemented.

Privacy

See PRIVACY.md — zero network calls, everything runs against files already in your workspace.

Development

npm install
npm run compile   # or: npm run watch
npm test

To build an installable package without publishing:

npx @vscode/vsce package

License

Apache License 2.0 — see LICENSE.