Contributing

This is a quick reference for Click-specific development tasks. For setting up the development environment and the general contribution workflow, see the Pallets quick reference and the detailed contributing guide.

Extra Test Environments

Click includes some extra test environments:

• tox r -e stress runs stress tests for race conditions in Click’s test runner.

  $ tox r -e stress
  

• tox r -e random runs tests in parallel in a random order to detect test pollution.

  $ tox r -e random
  

• A CI workflow (.github/workflows/test-flask.yaml) runs Flask’s test suite to catch downstream regressions.

Code Style

Avoid ternary expressions (x if cond else y): coverage cannot measure both branches. Use an explicit if/else block instead.

Do not add unnecessary dependencies. If a feature can be implemented with the standard library, do not pull in an external package for it.

Formatting

Wrap lines in Markdown files at 80 characters.