Unit Testing

Structured guidance for writing reliable, maintainable unit tests — covering test anatomy, mocking strategies, parameterized tests, TDD workflow, coverage strategy, and test organization across Python, TypeScript, and Go.

When to Activate

• Writing tests for a function, class, or module
• Setting up a test framework for a new project
• Mocking or stubbing external dependencies in tests
• Deciding what to unit test vs integration test
• Practising TDD (test-driven development) on a new feature
• Achieving or enforcing a coverage target
• Debugging a flaky or unclear test failure

Test Anatomy

Arrange / Act / Assert (AAA)