test-driven-development

Test-driven development prevents unreliable code by enforcing a Red-Green-Refactor workflow, requiring you to write a failing test first, implement minimal code to pass it, and then refactor safely.

Common unit testing anti-patterns to avoid include mocking real behavior and polluting production code with test-only methods, which compromise software quality and undermine the reliability of your tests.

To apply TDD to bug fixes, start by writing a failing test that reproduces the specific bug, implement the minimal code required to make the test pass, and then refactor the production code safely.

Test-driven development works for microservices by guiding you to drive feature implementation through requirements-based tests rather than implementation-biased assumptions, ensuring reliable and well-tested logic.

You should avoid test-driven development when implementation details are highly volatile or undefined, as the strict cycle requires clear, testable requirements to drive the production code effectively.

The Red-Green-Refactor cycle is a core testing workflow where you write a failing test, implement minimal code to pass the test, and then refactor the code to improve quality without changing behavior.