pr-to-go-linter

PR to Go Linter

Use this skill when a user asks to create a new custom Go linter based on a code pattern fixed in a pull request.

Goal

Convert one concrete PR pattern into a new go/analysis linter under pkg/linters/<name>/ with tests and runner registration.

Inputs

• Repository owner/name
• Pull request number
• Target linter name (kebab-case)

Workflow

1. Read PR metadata and changed files.
2. Read the PR diff and extract the repeated pattern that was fixed.
3. Define one precise diagnostic rule from that pattern.
4. Confirm no existing linter in pkg/linters/ already covers it.
5. Implement:
   • pkg/linters/<name>/<name>.go with exported Analyzer
   • pkg/linters/<name>/<name>_test.go using analysistest
   • pkg/linters/<name>/testdata/src/<name>/<name>.go fixtures with // want
   • cmd/linters/main.go registration in multichecker.Main(...)
6. Validate:
   • go test ./pkg/linters/<name>/...
   • go build ./cmd/linters
   • make golint-custom

Rule quality checks

• High signal, low false positives on this repository.
• Diagnostic is specific and fixable.
• Rule scope matches code in the PR (do not generalize beyond evidence).
• Do not change unrelated linter packages.

Example pattern source

For PR #33038 (Refactor pkg mutex sites to use deferred unlocks consistently), derive a linter idea that reports lock/unlock sections that manually unlock instead of deferring unlock immediately after lock when the function body matches the same cache/logger-style critical section pattern.

Output expectations

• Minimal implementation-only diff in pkg/linters/<name>/ and cmd/linters/main.go.
• Tests prove both flagged and non-flagged cases.
• PR summary explains: source PR, extracted pattern, and why the rule is safe.