Mode: Cognitive/Prompt-Driven — No standalone utility script; use via agent context.
Step 1: Identify Test Type
Determine what type of test is needed:
-
Unit Test: Component/function testing
-
Integration Test: Service/API integration
-
E2E Test: Full user flow testing
-
API Test: Endpoint testing
Step 2: Analyze Target Code
Examine code to test (Use Parallel Read/Grep/Glob):
-
Read component/function code
-
Identify test cases
-
Understand dependencies
-
Note edge cases
Step 3: Analyze Test Patterns
Review existing tests:
-
Read similar test files
-
Identify testing patterns
-
Note testing framework usage
-
Understand mocking strategies
Step 4: Generate Test Code
Create test following patterns:
-
Use appropriate testing framework
-
Follow project conventions
-
Include comprehensive coverage
-
Add edge cases and error scenarios
Step 5: Coverage Analysis
After generating tests, analyze coverage:
Check that generated tests cover all requirements:
-
Verify all functions/methods are tested
-
Check all branches are covered (if/else, switch, etc.)
-
Ensure all edge cases are tested
-
Validate error scenarios are covered
Validate tests are runnable:
-
Check test syntax is valid
-
Verify imports are correct
-
Ensure test framework is properly configured
-
Validate test setup/teardown is correct
Report coverage percentage:
-
Calculate line coverage (if possible)
-
Calculate branch coverage (if possible)
-
Report uncovered code paths
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Suggest additional tests for uncovered areas
Coverage Validation Checklist:
-
All public functions/methods have tests
-
All error paths are tested
-
All edge cases are covered
-
Tests are syntactically valid
-
Tests can be executed successfully
-
Coverage meets project thresholds (if defined) </execution_process>
import { render, screen, waitFor } from '@testing-library/react' import { describe, it, expect, vi } from 'vitest' import { UserProfile } from './user-profile'
describe('UserProfile', () => { it('renders user information', async () => { const mockUser = { id: '1', name: 'John', email: 'john@example.com' }
render(<UserProfile user={mockUser} />)
await waitFor(() => {
expect(screen.getByText('John')).toBeInTheDocument()
expect(screen.getByText('john@example.com')).toBeInTheDocument()
})
})
it('handles loading state', () => { render(<UserProfile user={null} loading />) expect(screen.getByTestId('loading')).toBeInTheDocument() })
it('handles error state', () => { render(<UserProfile user={null} error="Failed to load" />) expect(screen.getByText('Failed to load')).toBeInTheDocument() }) })
</code_example>
<code_example> Integration Test (API)
import { describe, it, expect, beforeAll, afterAll } from 'vitest'; import { createTestClient } from './test-client';
describe('Users API', () => { let client: TestClient;
beforeAll(() => { client = createTestClient(); });
afterAll(async () => { await client.cleanup(); });
it('creates a user', async () => { const response = await client.post('/api/users', { email: 'test@example.com', name: 'Test User', });
expect(response.status).toBe(201);
expect(response.data).toHaveProperty('id');
expect(response.data.email).toBe('test@example.com');
});
it('validates required fields', async () => { const response = await client.post('/api/users', {});
expect(response.status).toBe(400);
expect(response.data).toHaveProperty('errors');
}); });
</code_example>
<code_example> E2E Test (Cypress)
describe('User Authentication Flow', () => { beforeEach(() => { cy.visit('/login'); });
it('allows user to login', () => { cy.get('[data-testid="email-input"]').type('user@example.com'); cy.get('[data-testid="password-input"]').type('password123'); cy.get('[data-testid="login-button"]').click();
cy.url().should('include', '/dashboard');
cy.get('[data-testid="user-menu"]').should('be.visible');
});
it('shows error for invalid credentials', () => { cy.get('[data-testid="email-input"]').type('invalid@example.com'); cy.get('[data-testid="password-input"]').type('wrong'); cy.get('[data-testid="login-button"]').click();
cy.get('[data-testid="error-message"]')
.should('be.visible')
.and('contain', 'Invalid credentials');
}); });
</code_example>
Integration with QA Agent:
-
Creates comprehensive test suites
-
Generates test plans
-
Validates test quality
<best_practices>
-
Follow Patterns: Match existing test structure
-
Comprehensive Coverage: Test happy paths and edge cases
-
Clear Test Names: Descriptive test descriptions
-
Isolate Tests: Each test should be independent
-
Mock Dependencies: Use appropriate mocking strategies </best_practices>
Generate tests for a file
node .claude/skills/test-generator/scripts/main.cjs src/components/UserProfile.tsx
The tool will analyze the file and generate appropriate tests
</usage_example>
Iron Laws
-
ALWAYS analyze existing test patterns and framework conventions before generating any test code
-
NEVER generate tests that inspect implementation details — test only public behavior and outputs
-
ALWAYS include edge cases: null/undefined inputs, boundary values, and error scenarios for every tested unit
-
NEVER produce tests with shared mutable state — use beforeEach/afterEach to isolate every test
-
ALWAYS verify generated tests are syntactically valid and runnable before marking generation complete
Anti-Patterns
Anti-Pattern Why It Fails Correct Approach
Testing implementation details Breaks on refactor even when behavior is unchanged Test public API behavior and observable outputs
No assertions in test body Test always passes, catches nothing Add explicit assertions for every test case
Shared mutable state between tests Tests fail depending on execution order Use beforeEach/afterEach for full isolation
Magic numbers in assertions Unclear expected values, brittle tests Use named constants or descriptive fixture data
Missing error path tests Half coverage, silent failures in production Test both success and failure scenarios
Memory Protocol (MANDATORY)
Before starting: Read .claude/context/memory/learnings.md
After completing:
-
New pattern -> .claude/context/memory/learnings.md
-
Issue found -> .claude/context/memory/issues.md
-
Decision made -> .claude/context/memory/decisions.md
ASSUME INTERRUPTION: If it's not in memory, it didn't happen.