common-test-driven-development

Write unit tests before or alongside implementation code, following a test-driven development approach to ensure correctness and prevent regressions.

When to use

Use this skill when:

• Creating new functions, classes, methods, or modules
• Modifying existing business logic or behavior
• Fixing bugs (write a failing test that reproduces the bug first)
• Refactoring code (ensure tests exist and pass before and after changes)
• The user asks to implement any feature or logic

Instructions