test-driven-development

The test-driven development process requires writing a failing test before any implementation, adding minimal code to pass the test, and refactoring only after the test is green. This Red-Green-Refactor cycle prevents regressions and improves maintainability.

To start writing code using test-driven development, write a failing test for your new feature or bug fix first. Then implement the minimum production code required to make that test pass, and finally refactor the implementation while ensuring tests remain green.

Writing tests before implementation code enforces the test-first principle, which improves software design, prevents regressions, and ensures code quality. It guarantees that all production code is validated by a failing test from the outset.

Test-driven development is ideal for fixing bugs in agile workflows. You start by writing a failing test that reproduces the bug, then write minimal code to make the test pass, ensuring the regression is fixed and validated before moving forward.

You should refactor code during the Refactor phase of the test-driven development cycle, which occurs only after your tests are green. This ensures you can safely clean up the implementation without introducing regressions or breaking existing functionality.