A lint framework that writes better Python code for you.

Fixit is a lint framework that complements Flake8. It’s based on LibCST which makes it possible to provide auto-fixes. Lint rules are made easy to build through pattern matching, a test toolkit, and utility helpers (e.g. scope analysis) for non-trivial boilerplate. It is optimized for efficiency, easy to customize and comes with many builtin lint rules.

To install Fixit:

pip install fixit

Fixit provides CLI commands. To run built-in Fixit rules on existing code to get code quality suggestions:

python -m fixit.cli.run_rules

To apply autofix on existing code:

python -m fixit.cli.apply_fix

You can learn more about how to configure Fixit, build a lint rule, test a lint rule from our tutorials. Try it out with our notebook examples.

• Static Analysis at Scale: An Instagram Story.

Start by setting up and activating a virtualenv:

git clone git@github.com:Instagram/Fixit.git fixit
cd fixit
python3 -m venv ../fixit-env/  # just an example, put this wherever you want
source ../fixit-env/bin/activate
pip install --upgrade pip  # optional, if you have an old system version of pip
pip install -r requirements.txt -r requirements-dev.txt
# If you're done with the virtualenv, you can leave it by running:
deactivate

We use isort and black to format code. To format changes to be conformant, run the following in the root:

tox -e autofix

To run all tests, you'll need to install tox and do the following in the root: (use py37, py38 to choose from Python version 3.7 or 3.8):

tox -e py38

You can also run individual unit tests by specifying a module like this:

tox -e py38 -- fixit.common.tests.test_report

To run all test cases of a specific rule (e.g. NoInheritFromObjectRule):

tox -e py38 -- fixit.tests.NoInheritFromObjectRule

See the unittest documentation for more examples of how to run tests.

We use Pyre for type-checking. To verify types for the library, do the following in the root:

pyre --preserve-pythonpath check

To generate documentation, do the following in the root:

tox -e docs

Fixit is MIT licensed, as found in the LICENSE file.

• Privacy Policy
• Terms of Use