209: Testing argparse Applications

How do you test the argument parsing bit of an application that uses argparse?

This episode covers:

• Design for Test: Structuring your app or script so it's easier to test.
• pytest & capsys for testing stdout
• Adding debug and preview flags for debugging and testing
• And reverting to subprocess.run if you can't modify the code under test

Also, there's a full writeup and code samples available:

• Blog post: Testing argparse Applications 
• Code Repo

Help support the show AND learn pytest: 

• The Complete pytest course is now a bundle, with each part available separately.
  • pytest Primary Power teaches the super powers of pytest that you need to learn to use pytest effectively.
  • Using pytest with Projects has lots of "when you need it" sections like debugging failed tests, mocking, testing strategy, and CI
  • Then pytest Booster Rockets can help with advanced parametrization and building plugins.
• Whether you need to get started with pytest today, or want to power up your pytest skills, PythonTest has a course for you.