test-driven-development

The red-green-refactor workflow improves unit testing by enforcing a test-first cycle: you write a failing test, implement minimal code to pass it, then refactor for maintainability. This reduces bugs and prevents regressions early.

Test-driven development (TDD) is a coding discipline where you write failing tests before implementing features or bug fixes. You should apply TDD when starting new features or fixing bugs to define expected behavior and enable safer refactors.

To write a failing test before coding, define the expected behavior of your new feature in an executable test case. Implement the smallest amount of code required to make that test pass, ensuring modular and decoupled design.

Yes, test-driven development works for refactoring by validating behavior with automated tests. Writing tests first catches regressions early and drives modular, decoupled code through testable interfaces, ensuring safer quality assurance.

A limitation of using test-first discipline for bug fixes is the requirement for rigorous iteration and executable tests. Teams must invest time in writing failing tests before implementing minimal code, which may slow initial rapid prototyping.