Implement testing framework with Vitest, add unit tests for API routes and utility functions, and configure CI workflow for automated testing. Update package dependencies for testing libraries and add test scripts to package.json.

app/api/info/route.test.ts

@@ -0,0 +1,89 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { POST } from './route'
+import { NextRequest } from 'next/server'
+
+vi.mock('@/lib/youtube', () => ({
+  getVideoInfo: vi.fn(),
+}))
+
+import { getVideoInfo } from '@/lib/youtube'
+
+const mockGetVideoInfo = vi.mocked(getVideoInfo)
+
+function createRequest(body: object): NextRequest {
+  return new NextRequest('http://localhost:3000/api/info', {
+    method: 'POST',
+    body: JSON.stringify(body),
+    headers: { 'Content-Type': 'application/json' },
+  })
+}
+
+describe('POST /api/info', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('returns 400 when URL is missing', async () => {
+    const request = createRequest({})
+    const response = await POST(request)
+    const data = await response.json()
+
+    expect(response.status).toBe(400)
+    expect(data.success).toBe(false)
+    expect(data.error).toBe('URL is required')
+  })
+
+  it('returns 400 for invalid YouTube URL', async () => {
+    const request = createRequest({ url: 'https://vimeo.com/123' })
+    const response = await POST(request)
+    const data = await response.json()
+
+    expect(response.status).toBe(400)
+    expect(data.success).toBe(false)
+    expect(data.error).toBe('Invalid YouTube URL')
+  })
+
+  it('returns 500 when getVideoInfo fails', async () => {
+    mockGetVideoInfo.mockResolvedValue(null)
+
+    const request = createRequest({ url: 'https://youtube.com/watch?v=dQw4w9WgXcQ' })
+    const response = await POST(request)
+    const data = await response.json()
+
+    expect(response.status).toBe(500)
+    expect(data.success).toBe(false)
+    expect(data.error).toBe('Failed to get video info')
+  })
+
+  it('returns video info on success', async () => {
+    const mockVideoInfo = {
+      title: 'Test Video',
+      duration: 180,
+      thumbnail: 'https://example.com/thumb.jpg',
+      formats: [],
+    }
+    mockGetVideoInfo.mockResolvedValue(mockVideoInfo)
+
+    const request = createRequest({ url: 'https://youtube.com/watch?v=dQw4w9WgXcQ' })
+    const response = await POST(request)
+    const data = await response.json()
+
+    expect(response.status).toBe(200)
+    expect(data.success).toBe(true)
+    expect(data.videoInfo).toEqual(mockVideoInfo)
+  })
+
+  it('handles exceptions gracefully', async () => {
+    const consoleSpy = vi.spyOn(console, 'error').mockImplementation(() => {})
+    mockGetVideoInfo.mockRejectedValue(new Error('Network error'))
+
+    const request = createRequest({ url: 'https://youtube.com/watch?v=dQw4w9WgXcQ' })
+    const response = await POST(request)
+    const data = await response.json()
+
+    expect(response.status).toBe(500)
+    expect(data.success).toBe(false)
+    expect(data.error).toBe('Network error')
+    consoleSpy.mockRestore()
+  })
+})