TDD Process

Process Steps

Step 1: Red Phase

• Write a failing test for the target behavior
• Run the test suite on that specific file
• Gate: Failure must be on the assertion — not a syntax or configuration error
• Checkpoint: Present the test code and failure output before proceeding to implementation

Step 2: Green Phase

• Write the minimal code required to pass the test — nothing more
• Run the test file
• Checkpoint: Present the minimal implementation once tests pass

Step 3: Refactor Phase

• Clean up duplication, naming, class structures, and documentation
• Run the test suite after each micro-change
• Gate: Tests must remain green throughout