test-driven-development

To start writing unit tests first, write a failing test case for the new function before creating any implementation code. This test-driven workflow enforces the red-green-refactor cycle, requiring tests to fail initially, pass after implementation, and then undergo refactoring for optimized code quality.

The red-green-refactor cycle in test-driven development mandates writing a failing test first, implementing the minimum production code to make it pass, and then refactoring the code. This workflow prevents the delivery of bug-prone code by catching issues early in the creation process.

Maintainable code requires 80% or higher unit test line coverage. Additionally, integration tests must cover both the happy path and at least two error paths, alongside end-to-end tests for critical user journeys, to meet defined software quality standards.

Yes, test-driven development applies to building API endpoints. When creating a new endpoint, write failing tests for valid inputs, invalid inputs, and missing data scenarios first, then implement the endpoint logic to pass all tests before refactoring.

Writing failing tests before production code ensures the test accurately validates the intended logic and prevents untested code from being shipped. This strict test-first approach eliminates costly post-deployment debugging by catching behavioral issues early.

Yes, test-driven development requires integration tests covering both the happy path and two error paths. This ensures sufficient test depth to validate that the code correctly handles unexpected scenarios and maintains long-term maintainability.