test-driven-development

Test-driven development (TDD) is a software development methodology that enforces a strict Red-Green-Refactor cycle. You first write a failing test describing the desired behavior, implement minimal code to pass the test, and then refactor while ensuring tests remain green.

To start the Red-Green-Refactor cycle, write a failing test for your new feature. Next, write the smallest amount of implementation code necessary to make the test pass. Finally, refactor the production code while verifying all tests remain green.

Writing tests before implementation code improves software quality by guaranteeing all production code is preceded by a failing test. This test-first approach prevents regressions and ensures the code reliably meets requirements through continuous refactoring.

Test-driven development primarily addresses the problem of untested or poorly tested code by mandating a test-first approach for new production code. You use it when starting a new feature to ensure code quality and prevent regressions during subsequent refactoring.

The best way to guarantee code quality and prevent regressions in agile development is enforcing the Test-Driven Development methodology. It mandates that no production code is written without a preceding failing test, ensuring reliable and well-tested software.

You need to write a failing test during software development whenever you start a new feature. This test initially describes the desired behavior and fails, prompting you to write minimal implementation code to make it pass before refactoring.