skippy-cov

Overview

skippy-cov is a tool that optimizes your Python testing workflow by filtering tests based on code changes. It takes a diff file from git and a .coverage database (generated by coverage.py) to identify and run only the tests relevant to the modified code. This significantly reduces testing time and resources.

Usage

To use this, you first need to generate the following required files:

• Run Coverage Analysis: Generate a .coverage database using coverage.py via pytest-cov with test contexts

    pytest --cov=myproj --cov-context=test myproj/tests/

Then change your code and run

pytest --skippy-cov

In this case, skippy-cov will analyze the changes and run only the tests that are relevant to the modified code.

You can also use skippy-cov as a CLI on its own.

skippy-cov

that will list the tests selected.

Configuration

The inputs for skippy-cov are the coverage file (default: .coverage) and the diff information. By default, the diff is generated in the same way as a pull request (PR) on GitHub: only the changes introduced by your branch compared to the target branch are considered. This is done using the git diff <target>...HEAD (triple-dot) syntax.

You can specify the coverage file and a branch or ref to diff against (e.g., the main branch):

skippy-cov --diff main --coverage-file .coverage

or equivalently

pytest --skippy-cov --skippy-cov-diff main --skippy-cov-coverage-file .coverage

You can also provide a diff file:

git diff > changes.diff
skippy-cov --diff changes.diff --coverage-file .coverage

If you omit the --diff argument, it will default to the main branch as determined by your git remote (usually "main" or "master").

Advanced:
You may pass any valid git diff refspec to --diff, including triple-dot syntax (e.g., main...HEAD or origin/master...feature-branch). If you provide a triple-dot ref, it will be used as-is, giving you full control over the comparison range.

See skippy-cov --help for more information.

Contributing

See CONTRIBUTING.md for information on how to contribute to the project.

License

See LICENSE for licensing information.