TDD Red-Green-Refactor Cycle

Execute a comprehensive Test-Driven Development (TDD) workflow with strict red-green-refactor discipline:

[Extended thinking: This workflow enforces test-first development through coordinated agent orchestration. Each phase of the TDD cycle is strictly enforced with fail-first verification, incremental implementation, and continuous refactoring. The workflow supports both single test and test suite approaches with configurable coverage thresholds.]

Configuration

Coverage Thresholds

• -Minimum line coverage: 80%
• -Minimum branch coverage: 75%
• -Critical path coverage: 100%

Refactoring Triggers

• -Cyclomatic complexity > 10
• -Method length > 20 lines
• -Class length > 200 lines
• -Duplicate code blocks > 3 lines

Phase 1: Test Specification and Design

1. Requirements Analysis

• -Use Task tool with subagent_type="comprehensive-review::architect-review"
• -Prompt: "Analyze requirements for: $ARGUMENTS. Define acceptance criteria, identify edge cases, and create test scenarios. Output a comprehensive test specification."
• -Output: Test specification, acceptance criteria, edge case matrix
• -Validation: Ensure all requirements have corresponding test scenarios

2. Test Architecture Design

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Design test architecture for: $ARGUMENTS based on test specification. Define test structure, fixtures, mocks, and test data strategy. Ensure testability and maintainability."
• -Output: Test architecture, fixture design, mock strategy
• -Validation: Architecture supports isolated, fast, reliable tests

Phase 2: RED - Write Failing Tests

3. Write Unit Tests (Failing)

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Write FAILING unit tests for: $ARGUMENTS. Tests must fail initially. Include edge cases, error scenarios, and happy paths. DO NOT implement production code."
• -Output: Failing unit tests, test documentation
• -CRITICAL: Verify all tests fail with expected error messages

4. Verify Test Failure

• -Use Task tool with subagent_type="tdd-workflows::code-reviewer"
• -Prompt: "Verify that all tests for: $ARGUMENTS are failing correctly. Ensure failures are for the right reasons (missing implementation, not test errors). Confirm no false positives."
• -Output: Test failure verification report
• -GATE: Do not proceed until all tests fail appropriately

Phase 3: GREEN - Make Tests Pass

5. Minimal Implementation

• -Use Task tool with subagent_type="backend-development::backend-architect"
• -Prompt: "Implement MINIMAL code to make tests pass for: $ARGUMENTS. Focus only on making tests green. Do not add extra features or optimizations. Keep it simple."
• -Output: Minimal working implementation
• -Constraint: No code beyond what's needed to pass tests

6. Verify Test Success

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Run all tests for: $ARGUMENTS and verify they pass. Check test coverage metrics. Ensure no tests were accidentally broken."
• -Output: Test execution report, coverage metrics
• -GATE: All tests must pass before proceeding

Phase 4: REFACTOR - Improve Code Quality

7. Code Refactoring

• -Use Task tool with subagent_type="tdd-workflows::code-reviewer"
• -Prompt: "Refactor implementation for: $ARGUMENTS while keeping tests green. Apply SOLID principles, remove duplication, improve naming, and optimize performance. Run tests after each refactoring."
• -Output: Refactored code, refactoring report
• -Constraint: Tests must remain green throughout

8. Test Refactoring

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Refactor tests for: $ARGUMENTS. Remove test duplication, improve test names, extract common fixtures, and enhance test readability. Ensure tests still provide same coverage."
• -Output: Refactored tests, improved test structure
• -Validation: Coverage metrics unchanged or improved

Phase 5: Integration and System Tests

9. Write Integration Tests (Failing First)

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Write FAILING integration tests for: $ARGUMENTS. Test component interactions, API contracts, and data flow. Tests must fail initially."
• -Output: Failing integration tests
• -Validation: Tests fail due to missing integration logic

10. Implement Integration

• -Use Task tool with subagent_type="backend-development::backend-architect"
• -Prompt: "Implement integration code for: $ARGUMENTS to make integration tests pass. Focus on component interaction and data flow."
• -Output: Integration implementation
• -Validation: All integration tests pass

Phase 6: Continuous Improvement Cycle

11. Performance and Edge Case Tests

• -Use Task tool with subagent_type="unit-testing::test-automator"
• -Prompt: "Add performance tests and additional edge case tests for: $ARGUMENTS. Include stress tests, boundary tests, and error recovery tests."
• -Output: Extended test suite
• -Metric: Increased test coverage and scenario coverage

12. Final Code Review

• -Use Task tool with subagent_type="comprehensive-review::architect-review"
• -Prompt: "Perform comprehensive review of: $ARGUMENTS. Verify TDD process was followed, check code quality, test quality, and coverage. Suggest improvements."
• -Output: Review report, improvement suggestions
• -Action: Implement critical suggestions while maintaining green tests

Incremental Development Mode

For test-by-test development:

1. Write ONE failing test

2. Make ONLY that test pass

3. Refactor if needed

4. Repeat for next test

Use this approach by adding --incremental flag to focus on one test at a time.

Test Suite Mode

For comprehensive test suite development:

1. Write ALL tests for a feature/module (failing)

2. Implement code to pass ALL tests

3. Refactor entire module

4. Add integration tests

Use this approach by adding --suite flag for batch test development.

Validation Checkpoints

RED Phase Validation

• -[ ] All tests written before implementation
• -[ ] All tests fail with meaningful error messages
• -[ ] Test failures are due to missing implementation
• -[ ] No test passes accidentally

GREEN Phase Validation

• -[ ] All tests pass
• -[ ] No extra code beyond test requirements
• -[ ] Coverage meets minimum thresholds
• -[ ] No test was modified to make it pass

REFACTOR Phase Validation

• -[ ] All tests still pass after refactoring
• -[ ] Code complexity reduced
• -[ ] Duplication eliminated
• -[ ] Performance improved or maintained
• -[ ] Test readability improved

Coverage Reports

Generate coverage reports after each phase:

• -Line coverage
• -Branch coverage
• -Function coverage
• -Statement coverage

Failure Recovery

If TDD discipline is broken:

1. STOP immediately

2. Identify which phase was violated

3. Rollback to last valid state

4. Resume from correct phase

5. Document lesson learned

TDD Metrics Tracking

Track and report:

• -Time in each phase (Red/Green/Refactor)
• -Number of test-implementation cycles
• -Coverage progression
• -Refactoring frequency
• -Defect escape rate

Anti-Patterns to Avoid

• -Writing implementation before tests
• -Writing tests that already pass
• -Skipping the refactor phase
• -Writing multiple features without tests
• -Modifying tests to make them pass
• -Ignoring failing tests
• -Writing tests after implementation

Success Criteria

• -100% of code written test-first
• -All tests pass continuously
• -Coverage exceeds thresholds
• -Code complexity within limits
• -Zero defects in covered code
• -Clear test documentation
• -Fast test execution (< 5 seconds for unit tests)

Notes

• -Enforce strict RED-GREEN-REFACTOR discipline
• -Each phase must be completed before moving to next
• -Tests are the specification
• -If a test is hard to write, the design needs improvement
• -Refactoring is NOT optional
• -Keep test execution fast
• -Tests should be independent and isolated

TDD implementation for: $ARGUMENTS