name: testing description: Writes tests using Vitest and Testing Library. Use when creating unit tests, API tests, component tests, or mocking Firebase/external services. Includes test patterns, assertions, and coverage targets.

Testing Skill

Instructions

1. Place tests in src/__tests__/
2. Use describe/it/expect pattern
3. Mock Firebase with helpers in helpers/mock-firebase.ts
4. Run: pnpm test (watch) or pnpm test:run (once)

Test Template

import { describe, it, expect, beforeEach, vi } from 'vitest'

describe('functionName', () => {
  beforeEach(() => vi.clearAllMocks())

  it('should do something when condition', () => {
    const result = functionName(input)
    expect(result).toBe('expected')
  })

  it('should throw error for invalid input', () => {
    expect(() => functionName(null)).toThrow('Error')
  })
})

Common Assertions

expect(value).toBe(expected)
expect(value).toEqual({ key: 'value' })
expect(array).toContain(item)
expect(fn).toHaveBeenCalledWith(arg)
expect(async () => await fn()).rejects.toThrow()

Coverage Targets

• Statements: 80%
• Branches: 70%
• Functions: 80%

For mocking patterns, API testing, and component testing, see reference.md.