test-first-implementation

Test-driven development is implemented by guiding you through a red-green-refactor loop: writing a failing test for desired behavior, making it pass with the smallest change, then refactoring. It breaks features into small vertical slices for easier testing.

The red-green-refactor loop in TDD drives implementation from observable behavior. You first write a failing test (red), make it pass with minimal code (green), and then refactor without changing behavior.

Tests for behavior-driven development should focus on observable behavior, avoiding private implementation details. This ensures tests validate actual features rather than internal logic, enabling safe refactoring during the TDD workflow.

Test-first implementation requires a test framework and the ability to run tests locally. It does not mandate a specific framework, allowing you to apply the red-green-refactor loop within your existing development environment.

A regression-first fix workflow is applicable when features require clear behavior definitions before implementation. It is useful for test-first work, ensuring each step is tested and passes before moving to the next.

Breaking down a feature into small vertical slices for TDD yields easier testing and implementation. It ensures observable behavior is defined incrementally, driving the red-green-refactor loop effectively for each component.