test-driven-development

Test-driven development follows the THINK-RED-GREEN-REFACTOR cycle to write better code. You start by writing a failing test for a specific behavior, implement minimal code to pass it, and then refactor safely with the test acting as a safety net.

Refactoring code safely requires enforcing test-driven development to prevent regressions. By writing failing unit tests before implementation, you create a safety net that ensures changes do not break existing behaviors and facilitates confident refactoring.

Test-driven development is applicable to bug fixing and feature implementation across various programming languages. The methodology enforces writing a failing test reproducing the bug first, then implementing the fix to ensure code quality.

Test first development guards against common pitfalls like writing implementation before tests, skipping test failure verification, over-engineering, and testing multiple behaviors at once. It enforces TDD discipline by isolating behaviors and verifying failures.

TDD methodology may not suit exploratory prototyping where immediate code viability matters more than test coverage. The strict red-green-refactor cycle enforces discipline that might slow down rapid experimentation before settling on a design.

Test-driven development works for both new feature implementation and code refactoring tasks. It ensures code quality by enforcing the red-green-refactor cycle, preventing regressions whether you are adding behaviors or improving existing structure.