test-driven-development

Test-driven development starts by writing a failing test before any implementation code. You then write the minimal code required to pass that test, and finally refactor the implementation while ensuring the test still passes.

The Red-Green-Refactor cycle is the core TDD process where you write a failing test, write minimal code to make it pass, and then refactor the code. This cycle ensures software remains modular and prevents regressions.

Writing tests before implementation improves software design because it forces you to consider usability and modularity upfront. This approach naturally leads to more testable, decoupled code structures.

You need test-driven development for agile projects when starting any new feature to prevent regressions. It enforces writing failing tests first, ensuring new code does not break existing functionality.

Common TDD anti-patterns include skipping the failing test phase or writing excessive code beyond what is needed to pass. Avoid rationalizations that bypass the Red-Green-Refactor cycle to ensure reliable software.

Test-driven development does not require specific frameworks, as the methodology focuses on the Red-Green-Refactor process rather than tools. You apply the cycle using whatever testing libraries your software stack supports.