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Instructions

Clarify goals, constraints, and required inputs.

Apply relevant best practices and validate outcomes.

Provide actionable steps and verification.

If detailed examples are required, open

resources/implementation-playbook.md

.

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: Write ONE failing test Make ONLY that test pass Refactor if needed 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: Write ALL tests for a feature/module (failing) Implement code to pass ALL tests Refactor entire module 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: STOP immediately Identify which phase was violated Rollback to last valid state Resume from correct phase 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