Contributing

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Thanks for your interest in mix_affected. Bug reports, missed-test reports and pull requests are welcome.

The rule that matters

When in doubt, run everything. A selection that skips a test which would have failed is the worst outcome this library can produce. A change that narrows a selection must show, with a test, why the tests it drops cannot be affected. A change that falls back to a full run in a new case needs no such proof.

Reporting a missed test

If mix affected.report (or a red main branch) shows a test the selection missed, please open an issue with:

  1. the changed files (git diff --name-only --no-renames <base>...HEAD)
  2. the missed test file, and how it depends on the changed file (a macro, apply/3, a file it reads, config, ...)
  3. mix affected.files --files changed.txt --explain --format json output
  4. your Elixir and OTP versions

A minimal project that reproduces it is the fastest route to a fix.

Development

You need Elixir 1.18 or later. To run the :xref_json suite you need Elixir 1.19 or later.

mix deps.get
mix format --check-formatted && mix credo --strict && mix dialyzer && mix test

Fixture projects live in fixtures/, not test/, so their *_test.exs files never load in this suite. The integration tests copy a fixture to a temp dir, compile it and run the real tasks there.

Pull requests

  1. Add a test that fails without your change.
  2. Keep the gates above green.
  3. Add an entry under ## [Unreleased] in CHANGELOG.md.
  4. If you change the JSON output, the exit codes or the affected: config, update the README too. These are the public contract.