tdd-workflows-tdd-red

rmyndharis

•

6551216 months ago

Source Raw

Generate failing tests for the TDD red phase to define expected behavior and edge cases.

Quick Install

npxskills add rmyndharis/antigravity-skills--skill tdd-workflows-tdd-red

Instructions

Write comprehensive failing tests following TDD red phase principles.

[Extended thinking: Generates failing tests that properly define expected behavior using test-automator agent.]

Use this skill when

Starting the TDD red phase for new behavior
You need failing tests that capture expected behavior
You want edge case coverage before implementation

Do not use this skill when

You are in the green or refactor phase
You only need performance benchmarks
Tests must run against production systems

Instructions

Identify behaviors, constraints, and edge cases.
Generate failing tests that define expected outcomes.
Ensure failures are due to missing behavior, not setup errors.
Document how to run tests and verify failures.

Safety

Keep test data isolated and avoid production environments.
Avoid flaky external dependencies in the red phase.

Role

Generate failing tests using Task tool with subagent_type="unit-testing::test-automator".

Prompt Template

"Generate comprehensive FAILING tests for: $ARGUMENTS

Core Requirements

Test Structure
- Framework-appropriate setup (Jest/pytest/JUnit/Go/RSpec)
- Arrange-Act-Assert pattern
- should_X_when_Y naming convention
- Isolated fixtures with no interdependencies
Behavior Coverage
- Happy path scenarios
- Edge cases (empty, null, boundary values)
- Error handling and exceptions
- Concurrent access (if applicable)
Failure Verification
- Tests MUST fail when run
- Failures for RIGHT reasons (not syntax/import errors)
- Meaningful diagnostic error messages
- No cascading failures
Test Categories
- Unit: Isolated component behavior
- Integration: Component interaction
- Contract: API/interface contracts
- Property: Mathematical invariants

Framework Patterns

JavaScript/TypeScript (Jest/Vitest)

Mock dependencies with vi.fn() or jest.fn()
Use @testing-library for React components
Property tests with fast-check

Python (pytest)

Fixtures with appropriate scopes
Parametrize for multiple test cases
Hypothesis for property-based tests

Table-driven tests with subtests
t.Parallel() for parallel execution
Use testify/assert for cleaner assertions

Ruby (RSpec)

let for lazy loading, let! for eager
Contexts for different scenarios
Shared examples for common behavior

Quality Checklist

Readable test names documenting intent
One behavior per test
No implementation leakage
Meaningful test data (not 'foo'/'bar')
Tests serve as living documentation

Anti-Patterns to Avoid

Tests passing immediately
Testing implementation vs behavior
Complex setup code
Multiple responsibilities per test
Brittle tests tied to specifics

Edge Case Categories

Null/Empty: undefined, null, empty string/array/object
Boundaries: min/max values, single element, capacity limits
Special Cases: Unicode, whitespace, special characters
State: Invalid transitions, concurrent modifications
Errors: Network failures, timeouts, permissions

Output Requirements

Complete test files with imports
Documentation of test purpose
Commands to run and verify failures
Metrics: test count, coverage areas
Next steps for green phase"

Validation

After generation:

Run tests - confirm they fail
Verify helpful failure messages
Check test independence
Ensure comprehensive coverage

Example (Minimal)

// auth.service.test.ts
describe('AuthService', () => {
  let authService: AuthService;
  let mockUserRepo: jest.Mocked<UserRepository>;

  beforeEach(() => {
    mockUserRepo = { findByEmail: jest.fn() } as any;
    authService = new AuthService(mockUserRepo);
  });

  it('should_return_token_when_valid_credentials', async () => {
    const user = { id: '1', email: '[email protected]', passwordHash: 'hashed' };
    mockUserRepo.findByEmail.mockResolvedValue(user);

    const result = await authService.authenticate('[email protected]', 'pass');

    expect(result.success).toBe(true);
    expect(result.token).toBeDefined();
  });

  it('should_fail_when_user_not_found', async () => {
    mockUserRepo.findByEmail.mockResolvedValue(null);

    const result = await authService.authenticate('[email protected]', 'pass');

    expect(result.success).toBe(false);
    expect(result.error).toBe('INVALID_CREDENTIALS');
  });
});

Test requirements: $ARGUMENTS

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Write comprehensive failing tests following TDD red phase principles.

[Extended thinking: Generates failing tests that properly define expected behavior using test-automator agent.]

Use this skill when

Starting the TDD red phase for new behavior
You need failing tests that capture expected behavior
You want edge case coverage before implementation

Do not use this skill when

You are in the green or refactor phase
You only need performance benchmarks
Tests must run against production systems

Instructions

Identify behaviors, constraints, and edge cases.
Generate failing tests that define expected outcomes.
Ensure failures are due to missing behavior, not setup errors.
Document how to run tests and verify failures.

Safety

Keep test data isolated and avoid production environments.
Avoid flaky external dependencies in the red phase.

Role

Generate failing tests using Task tool with subagent_type="unit-testing::test-automator".

Prompt Template

"Generate comprehensive FAILING tests for: $ARGUMENTS

Core Requirements

Test Structure
- Framework-appropriate setup (Jest/pytest/JUnit/Go/RSpec)
- Arrange-Act-Assert pattern
- should_X_when_Y naming convention
- Isolated fixtures with no interdependencies
Behavior Coverage
- Happy path scenarios
- Edge cases (empty, null, boundary values)
- Error handling and exceptions
- Concurrent access (if applicable)
Failure Verification
- Tests MUST fail when run
- Failures for RIGHT reasons (not syntax/import errors)
- Meaningful diagnostic error messages
- No cascading failures
Test Categories
- Unit: Isolated component behavior
- Integration: Component interaction
- Contract: API/interface contracts
- Property: Mathematical invariants

Framework Patterns

JavaScript/TypeScript (Jest/Vitest)

Mock dependencies with vi.fn() or jest.fn()
Use @testing-library for React components
Property tests with fast-check

Python (pytest)

Fixtures with appropriate scopes
Parametrize for multiple test cases
Hypothesis for property-based tests

Table-driven tests with subtests
t.Parallel() for parallel execution
Use testify/assert for cleaner assertions

Ruby (RSpec)

let for lazy loading, let! for eager
Contexts for different scenarios
Shared examples for common behavior

Quality Checklist

Readable test names documenting intent
One behavior per test
No implementation leakage
Meaningful test data (not 'foo'/'bar')
Tests serve as living documentation

Anti-Patterns to Avoid

Tests passing immediately
Testing implementation vs behavior
Complex setup code
Multiple responsibilities per test
Brittle tests tied to specifics

Edge Case Categories

Null/Empty: undefined, null, empty string/array/object
Boundaries: min/max values, single element, capacity limits
Special Cases: Unicode, whitespace, special characters
State: Invalid transitions, concurrent modifications
Errors: Network failures, timeouts, permissions

Output Requirements

Complete test files with imports
Documentation of test purpose
Commands to run and verify failures
Metrics: test count, coverage areas
Next steps for green phase"

Validation

After generation:

Run tests - confirm they fail
Verify helpful failure messages
Check test independence
Ensure comprehensive coverage

Example (Minimal)

// auth.service.test.ts
describe('AuthService', () => {
  let authService: AuthService;
  let mockUserRepo: jest.Mocked<UserRepository>;

  beforeEach(() => {
    mockUserRepo = { findByEmail: jest.fn() } as any;
    authService = new AuthService(mockUserRepo);
  });

  it('should_return_token_when_valid_credentials', async () => {
    const user = { id: '1', email: '[email protected]', passwordHash: 'hashed' };
    mockUserRepo.findByEmail.mockResolvedValue(user);

    const result = await authService.authenticate('[email protected]', 'pass');

    expect(result.success).toBe(true);
    expect(result.token).toBeDefined();
  });

  it('should_fail_when_user_not_found', async () => {
    mockUserRepo.findByEmail.mockResolvedValue(null);

    const result = await authService.authenticate('[email protected]', 'pass');

    expect(result.success).toBe(false);
    expect(result.error).toBe('INVALID_CREDENTIALS');
  });
});

Test requirements: $ARGUMENTS