piranha-python

An implementation of Uber's Piranha: a tool to automatically detect and remove usages of a given feature flag preserving the code's behavior.

Installation

Available for installation (for now) from the test Pypi's repo:

pip install -i https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple/ piranha-python

Please notice that this is still an extremely early and incomplete version!

Usage

Start by initializing libCST's codemod commands in the project into which you'd like to run Piranha:

python3 -m libcst.tool initialize .

Then add piranha to the modules section inside the generated .libcst.codemod.yaml file. The modules section should look like this:

modules:
- 'libcst.codemod.commands'
- 'piranha'

Then, finally, run Piranha passing the name of the feature flag that must be removed and of the directory where it should look for Python source files:

python3 -m libcst.tool codemod codemods.PiranhaCommand --flag-name <FEATURE_FLAG_NAME> <directory_path>

Use the following command to check further options available to use from libCST's codemod and additional arguments that can be passed to Piranha:

python3 -m libcst.tool codemod codemods.PiranhaCommand -h

Some intended features for upcoming versions:

• Support removing feature flag references from test code;
• Customize whether a feature flag is used as treatment or control;
• Customize how the feature flag is resolved (i.e. Piranha's receiverType and methodName configs);
• Better integration with Django (maybe?);
• Better integration with Flask (maybe?);