tdd

The red-green-refactor cycle in test-driven development involves writing a failing test, implementing just enough code to pass it, then refactoring for clarity. This iterative process guides design decisions and reduces software defects.

Implementing features using vertical slices with TDD requires delivering thin, end-to-end functionality one slice at a time. You define a minimal failing test per slice and iterate through red, green, and refactor steps.

Align test-driven development with acceptance criteria by treating each story or PRD reference as a driver for test creation. You write tests that validate specific acceptance criteria before implementing the feature code.

You must select a test framework before writing tests first, but no specific framework is mandated. The workflow adapts to your chosen framework to drive the red-green-refactor loop across your project.

Use strict TDD cycles when you need to enforce design decisions, reduce defects, and improve long-term maintainability. Writing tests after implementation does not guide code structure or catch design flaws early.

The best way to refactor code during a TDD workflow is to perform it only after the minimal implementation passes the test. This ensures behavior remains unchanged while you improve code clarity and maintainability.