Unit tests: when you mock every single important part of the application and then all tests pass always E2E tests: when you fail a test because the windows input stack decided your mouse click wasnt worth anything Integration tests: testing a viewmodel which references 46 different UI frameworks and breaks MVVM purity in ways never seen before
One question. For Unit-test and E2E, it is rather easy to establish how much you covered, since the scenario's are rather clear. How does one do that proper for integrations, for there are so many specific combinations.
