test-driven-development

Test-driven development enforces a Red-Green-Refactor cycle that starts with a failing test to define expected behavior, reducing bugs by ensuring production code is explicitly driven by requirements. It guides teams through writing minimal code to pass tests and careful refactoring that preserves behavior.

To start test-driven development, write a failing unit test that defines the desired feature behavior, then implement the minimal production code needed to make that test pass, and finally refactor the code while preserving the verified behavior.

Yes, test-driven development is applicable to bug fixes and refactors across any tech stack. It guides teams through Red-Green-Refactor cycles to catch regressions early and maintain real tests that validate explicit requirements.

The best way to maintain real tests is to follow careful refactoring practices that preserve behavior while avoiding test cheats or over-engineering. This ensures production code remains driven by explicit requirements without artificial test passes.

You should avoid test-driven development when over-engineering risks outweigh behavior validation benefits, or when writing minimal production code to pass failing tests becomes impractical for the specific feature scope.

Test-driven development requires a failing test first to explicitly define the expected behavior before coding. This ensures the production code written is minimal and directly driven by the actual requirements, reducing bugs and guiding design.