Contributing

Contributions are welcome. go-ruby-regexp/regexp is built to a small set of non-negotiable rules — they are what keep the engine pure-Go, correct, and Ruby-compatible. Please read these before opening a pull request.

Hard rules

• Build from source — no vendoring. Everything compiles from source. Do not reach for prebuilt binaries or vendored blobs as a shortcut; being able to compile from source is a guarantee of independence.
• 100% test coverage target, enforced in CI. New code ships with tests, and coverage is a CI gate. Fill the error branches, not just the happy path.
• All GitHub content in English. Issues, pull requests, commits, comments, and discussions are English-only.
• Differential testing against Onigmo/MRI. Correctness is defined by reference Ruby. A corpus of (pattern, input) pairs is run through both Ruby and this engine, and the match span, captures, and named groups are compared exactly — not approximated from memory. Onigmo's own test corpus is ported as fixtures, and property/fuzz tests check the parser for crashes.
• Pure Go, cgo disabled. The whole point is a single static binary with no C toolchain. Code must build with CGO_ENABLED=0. If a feature seems to need C, it needs a pure-Go path instead.
• The ReDoS budget always terminates. Every match must finish within the deterministic timeout/step budget. A change that can make matching run unbounded is a bug, no matter how fast the common case is — see ReDoS hardening.

Workflow

1. Pick or open an issue describing the change.
2. Work test-first: add the differential / unit tests, then make them pass.
3. Run the full suite with coverage and confirm the gate is green.
4. Open a PR in English, referencing the issue.

Where things live

The engine — scanner/parser, compiler, backtracking VM, and the public API — is in github.com/go-ruby-regexp/regexp. This documentation site is in github.com/go-ruby-regexp/docs. Start from the Architecture overview and the Roadmap to find the right place for your change.