majiayu000/claude-skill-registry-data/typescript-testing-cooldaemon-dotfiles

describe('UserService', () => {
  describe('createUser', () => {
    it('creates user with valid input', async () => {
      // Arrange
      const input = { name: 'Alice', email: 'alice@example.com' }
      // Act
      const user = await userService.createUser(input)
      // Assert
      expect(user.id).toBeDefined()
    })
  })
})

afterEach(() => {
  jest.clearAllMocks()  // Vitest: vi.clearAllMocks()
  jest.restoreAllMocks() // Vitest: vi.restoreAllMocks()
})

// GOOD: Spy on specific method
const spy = jest.spyOn(service, 'save')
// AVOID: Full module mock when not needed
jest.mock('./service')

// Use async/await
it('fetches data', async () => {
  const data = await fetchData()
  expect(data).toBeDefined()
})
// Use rejects for error cases
await expect(fetchData()).rejects.toThrow('Network error')

vitest bench                    # Run all benchmarks
vitest bench --reporter=verbose # Detailed output

bench('operation', () => { /* code */ }, {
  time: 1000,       // ms to run (default: 100)
  iterations: 100,  // minimum iterations
  warmupTime: 200,  // warmup before measuring
})