As much as possible

• Use pytest to make your testing life easier.
• Generalize your tests using hypothesis, but if in a pinch, use hard-coded examples and annotate where to generalize later.
• Tests should run under 500 ms per test, but this is not a hard rule.
• Hit as many lines of code as you can, but don't rely on test coverage to be satisfied with a test.
• Use your tests to re-design code to be easier to use, and hence, test.