This is a form of Data-Driven testing. The “Act” step is the same for all the tests, but the Arrange and Assert parts are parameterized.
Explain previous concepts:
Review the test cases in Shopping Basket Test Design Kata. Insert a bug (change 0.05 to 0.07 so the five percent discount case is wrong) and run the tests. Look at the failure messages. Which test design gives the best feedback?
Explain that this is a form of Data-Driven testing. The “Act” step is the same for all the tests, but the Arrange and Assert parts are parameterized. Show how to do this with Doctest (ie it’s not very easy at present).
Ask them to write new tests for the Shopping Basket implementation. When they have them working, ask them to re-insert the bug so one of the cases fails. Make sure the feedback is useful.
Note down your most important takeaways on the topic of Test Design.