Test Specialist

What This Does

Complete testing guidance for JavaScript/TypeScript projects. Write unit, integration, and E2E tests. Analyze bugs systematically. Identify coverage gaps. Detect potential issues proactively.

---

Quick Start

Step 1: Navigate to Your Project

cd ~/your-js-project

Step 2: Download the Template

Click Download above, then:

mv ~/Downloads/CLAUDE.md ./

Step 3: Start Testing

claude

Then ask: "Help me write tests for the user authentication module"

---

Testing Approach

Arrange-Act-Assert Pattern

describe('UserService', () => {
  it('should create a new user', async () => {
    // Arrange
    const userData = { email: 'test@example.com', name: 'Test' };

    // Act
    const user = await userService.create(userData);

    // Assert
    expect(user.email).toBe('test@example.com');
  });
});

---

Testing Types

Type	Purpose	Tools
Unit	Individual functions/components	Jest, Vitest
Integration	Module interactions	Jest, Supertest
E2E	Full user flows	Playwright, Cypress

---

Example Prompts

Test Writing

• "Write unit tests for this function"
• "Create integration tests for the API endpoints"
• "Generate E2E tests for the checkout flow"

Bug Analysis

• "Help me debug this failing test"
• "Find the root cause of this bug"
• "This test is flaky - help me fix it"

Coverage

• "Find untested code in this project"
• "Which files need more test coverage?"
• "Prioritize what to test next"

---

Bug Analysis Process

1. Reproduce: Confirm the issue exists
2. Isolate: Find the minimal reproduction case
3. Root Cause: Identify why it happens
4. Fix: Implement the solution
5. Validate: Add tests to prevent regression

---

Common Bug Patterns

Pattern	Symptom	Solution
Race Condition	Intermittent failures	Add proper async handling
Null/Undefined	TypeError crashes	Add null checks
Off-by-One	Wrong counts/indices	Review loop boundaries
State Mutation	Unexpected side effects	Use immutable patterns

---

Test Coverage Strategy

Priority Order:

1. Critical business logic
2. Edge cases and error handling
3. Happy path flows
4. Integration points
5. UI components

---

Security Testing

Include tests for:

• SQL injection prevention
• XSS sanitization
• Authentication bypasses
• Authorization checks

---

Tips

• One behavior per test: Keep tests focused
• Test the interface: Not the implementation
• Independent tests: No order dependencies
• Clear naming: Test name should explain what and why