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.

lib/utils.test.ts

@@ -0,0 +1,122 @@
+import { describe, it, expect } from 'vitest'
+import { isValidYouTubeUrl, extractYouTubeId, isValidYouTubeId, cn, formatDuration } from './utils'
+
+describe('isValidYouTubeUrl', () => {
+  it('accepts standard youtube.com watch URLs', () => {
+    expect(isValidYouTubeUrl('https://www.youtube.com/watch?v=dQw4w9WgXcQ')).toBe(true)
+    expect(isValidYouTubeUrl('http://www.youtube.com/watch?v=dQw4w9WgXcQ')).toBe(true)
+    expect(isValidYouTubeUrl('https://youtube.com/watch?v=dQw4w9WgXcQ')).toBe(true)
+  })
+
+  it('accepts youtu.be short URLs', () => {
+    expect(isValidYouTubeUrl('https://youtu.be/dQw4w9WgXcQ')).toBe(true)
+    expect(isValidYouTubeUrl('http://youtu.be/dQw4w9WgXcQ')).toBe(true)
+  })
+
+  it('accepts URLs without protocol', () => {
+    expect(isValidYouTubeUrl('www.youtube.com/watch?v=dQw4w9WgXcQ')).toBe(true)
+    expect(isValidYouTubeUrl('youtube.com/watch?v=dQw4w9WgXcQ')).toBe(true)
+  })
+
+  it('rejects non-YouTube URLs', () => {
+    expect(isValidYouTubeUrl('https://vimeo.com/123456')).toBe(false)
+    expect(isValidYouTubeUrl('https://google.com')).toBe(false)
+    expect(isValidYouTubeUrl('not a url')).toBe(false)
+    expect(isValidYouTubeUrl('')).toBe(false)
+  })
+
+  it('rejects YouTube domain without path', () => {
+    expect(isValidYouTubeUrl('https://youtube.com')).toBe(false)
+    expect(isValidYouTubeUrl('https://youtube.com/')).toBe(false)
+  })
+})
+
+describe('extractYouTubeId', () => {
+  it('extracts ID from standard watch URLs', () => {
+    expect(extractYouTubeId('https://www.youtube.com/watch?v=dQw4w9WgXcQ')).toBe('dQw4w9WgXcQ')
+    expect(extractYouTubeId('https://youtube.com/watch?v=abc123XYZ_-')).toBe('abc123XYZ_-')
+  })
+
+  it('extracts ID from youtu.be short URLs', () => {
+    expect(extractYouTubeId('https://youtu.be/dQw4w9WgXcQ')).toBe('dQw4w9WgXcQ')
+  })
+
+  it('extracts ID from embed URLs', () => {
+    expect(extractYouTubeId('https://www.youtube.com/embed/dQw4w9WgXcQ')).toBe('dQw4w9WgXcQ')
+  })
+
+  it('extracts ID from /v/ URLs', () => {
+    expect(extractYouTubeId('https://www.youtube.com/v/dQw4w9WgXcQ')).toBe('dQw4w9WgXcQ')
+  })
+
+  it('handles URLs with extra parameters', () => {
+    expect(extractYouTubeId('https://www.youtube.com/watch?v=dQw4w9WgXcQ&t=120')).toBe('dQw4w9WgXcQ')
+    expect(extractYouTubeId('https://youtu.be/dQw4w9WgXcQ?t=120')).toBe('dQw4w9WgXcQ')
+  })
+
+  it('returns null for invalid URLs', () => {
+    expect(extractYouTubeId('https://vimeo.com/123456')).toBe(null)
+    expect(extractYouTubeId('not a url')).toBe(null)
+    expect(extractYouTubeId('')).toBe(null)
+  })
+})
+
+describe('isValidYouTubeId', () => {
+  it('accepts valid 11-character IDs', () => {
+    expect(isValidYouTubeId('dQw4w9WgXcQ')).toBe(true)
+    expect(isValidYouTubeId('abc123XYZ_-')).toBe(true)
+    expect(isValidYouTubeId('AAAAAAAAAAA')).toBe(true)
+    expect(isValidYouTubeId('00000000000')).toBe(true)
+  })
+
+  it('rejects IDs with wrong length', () => {
+    expect(isValidYouTubeId('dQw4w9WgXc')).toBe(false)
+    expect(isValidYouTubeId('dQw4w9WgXcQQ')).toBe(false)
+    expect(isValidYouTubeId('')).toBe(false)
+  })
+
+  it('rejects IDs with invalid characters', () => {
+    expect(isValidYouTubeId('dQw4w9WgXc!')).toBe(false)
+    expect(isValidYouTubeId('dQw4w9WgXc@')).toBe(false)
+    expect(isValidYouTubeId('dQw4w9 gXcQ')).toBe(false)
+  })
+})
+
+describe('cn', () => {
+  it('merges class names', () => {
+    expect(cn('foo', 'bar')).toBe('foo bar')
+  })
+
+  it('handles conditional classes', () => {
+    expect(cn('foo', false && 'bar', 'baz')).toBe('foo baz')
+    expect(cn('foo', true && 'bar', 'baz')).toBe('foo bar baz')
+  })
+
+  it('deduplicates tailwind classes', () => {
+    expect(cn('p-4', 'p-2')).toBe('p-2')
+    expect(cn('text-red-500', 'text-blue-500')).toBe('text-blue-500')
+  })
+})
+
+describe('formatDuration', () => {
+  it('formats seconds into mm:ss', () => {
+    expect(formatDuration(0)).toBe('0:00')
+    expect(formatDuration(5)).toBe('0:05')
+    expect(formatDuration(59)).toBe('0:59')
+    expect(formatDuration(60)).toBe('1:00')
+    expect(formatDuration(61)).toBe('1:01')
+    expect(formatDuration(125)).toBe('2:05')
+  })
+
+  it('handles longer durations', () => {
+    expect(formatDuration(600)).toBe('10:00')
+    expect(formatDuration(3600)).toBe('60:00')
+    expect(formatDuration(3661)).toBe('61:01')
+  })
+
+  it('handles decimal seconds by flooring', () => {
+    expect(formatDuration(5.7)).toBe('0:05')
+    expect(formatDuration(59.9)).toBe('0:59')
+    expect(formatDuration(60.1)).toBe('1:00')
+  })
+})