test-driven-development

The Red-Green-Refactor cycle in test-driven development is an iterative process where you write a failing test, create minimal code to pass it, and then refactor to improve robustness and code quality.

To start writing tests before implementation code, identify your new feature scenarios and write a failing test for them. Only after the test fails should you write the minimal production code required to make it pass.

Yes, you can use test-driven development for bug fixes and refactoring. You enforce TDD by writing a failing test that reproduces the bug or regression before modifying production code to ensure software robustness.

You need test-driven development in agile software development when you want to prevent bugs, ensure code quality, and build a regression safety net before writing new features or modifying existing modules.

Test-driven development prevents regressions when adding a user authentication module by mandating failing tests for login, logout, and password reset scenarios before writing the actual implementation code.