Contributing

Development Setup

Requirements: Go 1.26+

git clone https://github.com/LarsArtmann/gogenfilter.git
cd gogenfilter
go mod download

Building

go build ./...

Testing

# Run all tests
go test ./...

# With race detector
go test -race ./...

Linting

Uses golangci-lint v2:

golangci-lint run

CI

All pull requests must pass:

• go build ./... — compiles cleanly
• go test -race -cover ./... — tests pass with race detection
• go vet ./... — no vet warnings
• golangci-lint run — no new lint issues

Code Style

• Table-driven tests where possible
• t.Parallel() within t.Run() for test isolation
• Functional options pattern for configuration
• Strong types over runtime checks
• Early returns over nested conditionals

Adding a Generator

1. Add a FilterOption and FilterReason const with the same string value in types.go
2. Add a detector entry in the detectors table in detection.go
3. Implement matchFilename (Phase 1) and/or checkContent (Phase 2) functions
4. Add test fixtures in testdata/
5. AllFilterOptions() and AllFilterReasons() update automatically

Documentation Generation (gendocs)

The detectors table in detection.go is the single source of truth for all generator data. The cmd/gendocs binary reads this table and generates documentation artifacts automatically.

Running gendocs

go generate ./...

This updates five output files:

• website/src/data/generators.json — consumed by Astro components
• README.md — generator tables (between <!-- gendocs:*:start/end --> markers)
• website/src/content/docs/generators.mdx — detection table + tool count
• website/src/content/docs/api/detection.mdx — per-generator function table
• doc.go — package comment generator list

Adding Website Metadata

Each detector needs presentation data (display name, logo, example filename) that isn’t derivable from Go source. Add this to the websiteMetadata map in cmd/gendocs/main.go. If you add a detector without metadata, gendocs will fail with a validation error.

CI Enforcement

CI runs go generate ./... && git diff --exit-code to verify generated docs are fresh. If you modify the detectors table, always run go generate ./... and commit the output.

Website Development

The website uses Astro v6 + Starlight + Tailwind v4. The color system uses a warm-stone background palette with a three-color accent rotation (cyan, amber, emerald). See docs/adr/001-color-system.md for the full decision record and instructions for adding new accent colors.

Pull Requests

• Ensure all tests pass: go test -race ./...
• Ensure linting passes: golangci-lint run
• Add tests for new functionality
• Keep changes focused and atomic