Contributing

indycheck is open source and contributions are welcome — bug reports, rule corrections, new bindings, docs and examples.

Before you start

• Discuss first for big changes. Open an issue describing what you want to change before writing a lot of code — especially for new validators or new language bindings.
• Never use real personal data. Test values in issues, PRs and tests must be synthetic (like AAAPL1234C or 234567890124). Never paste a real person’s PAN, Aadhaar, GSTIN or mobile number anywhere in the repo.
• One Rust core. All validation rules live in the Rust crate. Language bindings are thin wrappers — do not re-implement rules in JavaScript or Python.

How to contribute

1. Fork the repo and clone your fork.
2. Create a branch: git checkout -b fix/pan-holder-type or git checkout -b docs/hindi-errors.
3. Make your change, with tests.
4. Run the checks (see below) and make sure everything passes.
5. Open a pull request against main, describing what changed and why, with before/after examples.

Rules for validation changes

• Every rule change needs a test with a valid and an invalid example, plus the official source for the rule (e.g. UIDAI’s Verhoeff note, the GSTN check-digit algorithm, RBI’s IFSC format).
• Error code values are a public API — never rename or remove one without a major-version discussion. Add new codes instead.
• Every failure path must produce both reason_en and reason_hi.
• Keep the result shape identical across JS, Python and Rust.

Running the checks

# Rust core + all tests
cargo test

# JavaScript binding (Node 18+)
cd packages/indycheck-js && npm install && npm test

# Python binding (Python 3.9+)
cd packages/indycheck-py && pip install -e . && pytest

# This website
cd website && npm install && npm run build

Docs contributions

Docs live in website/src/content/docs/ (English for v0.2.0) and the landing/playground pages in website/src/pages/. Every doc page should have: real valid + invalid examples, a code sample in at least JavaScript, and the honest-limits note. Check your change with npm run build in website/.

Code style

• Rust: cargo fmt and cargo clippy clean.
• JavaScript/TypeScript: 2-space indent, single quotes, semicolons (see .prettierrc).
• Keep functions small and pure — validators take a string and return a result; no I/O, no globals, no network.

Reporting a bug

Open an issue with:

1. The validator and the exact input (synthetic data only).
2. What indycheck returned (ok, code).
3. What you expected, and the official source for the rule.
4. Your environment: package version, language, OS.

Security issues (for example, a validation bypass with real-world impact): please open a GitHub issue marked security rather than posting a public proof of concept.