Testability Forces Modularity
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Hard-to-test code is a design smell: if a class is hard to test, it is doing too much. Too many input combinations, too many side effects, too many conflated concerns. The cure is extraction. Writing unit tests exerts pressure toward smaller, focused modules because the test demands a unit small enough to exercise in isolation.
Connections
- 🌳Coverage Metrics Are Misleading
- 🌳Law of Demeter and Testing
- 🌳Minimize Public Surface for Testability
- 🌳Mocks vs. Stubs: When to Use Which
- 🌳Reduce Cyclomatic Complexity
- 🌳Testability Forces Dependency Injection
- 🌳Tests as a Refactoring Safety Net
- 🌳Tests as Executable Documentation
- 🌳Tests as First Customer
- 🌳Tests Prune the Debugging Search Space
- 🪶The merits of unit tests — Part 3