test-driven-development

Test-driven development (TDD) is a software development process where you write failing tests before production code. The red-green-refactor cycle guides you to write a failing test, implement minimal code to pass it, then refactor for maintainability.

To fix bugs using a test-first workflow, you write a focused, reproducible unit test that fails and captures the bug, then implement the minimal production code required to make that test pass, ensuring correctness and preventing future regressions.

To start writing unit tests before implementing features, define a small, focused test that specifies the desired behavior and initially fails. Then, write just enough production code to satisfy the test's requirements and make it pass.

Yes, test-driven development enforces deterministic test execution by requiring explicit test-first patterns and disciplined workflow steps. This quality assurance approach ensures code correctness, reproducible results, and safer deployments through strict testing.

You should avoid a test-first approach when exploring rapid prototypes where requirements are highly volatile, as the strict red-green-refactor cycle and deterministic unit tests require clear, defined specifications before writing production code.