• Group tests in a class if more than one test is needed for a given function/functionality
• Prefer black-box tests (no mocks) if possible, to avoid testing implementation details.
• Avoid unnecessary comments/docstrings: the code must be self-explanatory as much as possible.
• Quality > quantity: having high quality understandable tests is better than a ton of unnecessary tests.

Unit tests

Scope

Testing one function, method, or functionality

Recommendations

• Focus on the function goal to define the test cases.
• Testing corner cases is not mandatory. Sometimes we prefer a function to fail rather than being robust to unwanted scenarii.
• Unit tests on their own should provide a coverage close to 100%.

Functional or end-to-end tests

Scope

Testing the main functionalities of the API as seen from a user point-of-view, or testing behaviors hard to test in a unit style.

Recommendations

• Such tests here should be added wisely (they take usually more time to run)
• Be careful of test time. Testing few varied scenarios is more important than trying to test all scenarios.
• This is not implemented yet, but ideally those tests should not count against coverage.