test-driven-development

Test-driven development prevents untested code by enforcing a strict Red-Green-Refactor cycle, requiring developers to write failing tests first and verifying them in CI before writing minimal implementation code.

The Red-Green-Refactor cycle in TDD involves writing a failing test, implementing the minimal code required to pass that test, and then refactoring the code while maintaining a green CI status.

To implement a feature using TDD, write a failing test for the feature, commit it to verify failure in CI, write minimal code to pass the test, and finally refactor while ensuring CI remains green.

Yes, a Continuous Integration environment is required to verify that initial tests fail before implementation and to confirm that passing tests remain green after writing code and refactoring.

You should refactor code during test-driven development only after writing the minimal code to make the failing test pass, ensuring the Continuous Integration environment maintains a green status throughout the process.