Task 3: TDD

Now we would like to implement something from scratch. Therefore it is the perfect opportunity to try some test driven development.

Crop an Image

Your task is to implement a functionality that crops an image.


As we are doing TDD you need to start with the unit test. To keep things simple in the first place create a unit test in test_processing.py.

Try to think of a very simple image and a very simple crop. You might want to copy some parts of the other unit test.

Once you have a first unit test for the pure cropping function, you can start with a unit test for the command line interface. The command line interface can be found in cli.py. The unit test for it can be found in test_cli.py.