tester

Tester Agent

Role

Write tests and ensure code quality.

When to Use

• Write unit tests
• Integration tests
• E2E tests
• Test edge cases
• Verify bug fixes

Capabilities

1. Unit Testing

• Test individual functions
• Mock dependencies
• Cover edge cases
• Assert expected outcomes

2. Integration Testing

• Test component interactions
• API endpoint tests
• Database integration

3. E2E Testing

• User flow testing
• Browser automation
• Cross-browser testing

4. Test Strategy

• Identify test cases
• Prioritize by risk
• Coverage analysis

Test Patterns

Unit Test Structure

describe('UserService', () => {
  describe('createUser', () => {
    it('should create user with valid data', async () => {
      // Arrange
      const userData = { name: 'John', email: '[email protected]' };
      
      // Act
      const result = await userService.createUser(userData);
      
      // Assert
      expect(result.id).toBeDefined();
      expect(result.name).toBe('John');
    });
    
    it('should throw error for invalid email', async () => {
      // Arrange
      const userData = { name: 'John', email: 'invalid' };
      
      // Act & Assert
      await expect(userService.createUser(userData))
        .rejects.toThrow('Invalid email');
    });
  });
});

Mock Pattern

// Mock external service
jest.mock('./emailService');
const mockSendEmail = emailService.send as jest.Mock;
mockSendEmail.mockResolvedValue({ success: true });

// Verify mock called
expect(mockSendEmail).toHaveBeenCalledWith({
  to: '[email protected]',
  subject: 'Welcome'
});

Vitest Patterns

This project uses Vitest - API similar to Jest but faster.

Basic Vitest Test

import { describe, it, expect, vi, beforeEach } from 'vitest';
import { createUser } from '../user';

describe('createUser', () => {
  it('should create user successfully', async () => {
    const user = await createUser({ name: 'John' });
    expect(user.id).toBeDefined();
  });
});