superpowers:test-driven-development

Test-driven development is a workflow where you write a failing unit test before implementing production code. You iterate through a strict Red-Green-Refactor cycle, ensuring minimal code is written to pass the test and prevent regressions.

Start TDD for bug fixes by writing a failing test that captures the intended behavior, then implement the simplest code to pass it. This test-first approach documents behavior and provides guardrails for safe refactoring across software projects.

You should use real tests over mocks in test-driven development to accurately document intended behavior. Executable tests validate actual software quality and prevent regressions, whereas excessive mocks can bypass real integration failures.

Test-driven development applies across diverse software projects, teams, and stacks. The Red-Green-Refactor cycle requires no specific dependencies, making it universally applicable for feature development, bug fixes, and refactoring.

Writing failing tests first clarifies the intended behavior before implementation, driving design decisions and preventing regression. This approach ensures every piece of production code is justified by a test and maintains strict software quality.

The strict Red-Green-Refactor cycle requires disciplined adherence to writing minimal production code. Teams must avoid skipping the failing test phase, as doing so compromises the test-first mechanism that guards against regressions.