feat: title/artist normalization and matching

server/test/matcher.test.ts

@@ -0,0 +1,59 @@
+import { describe, it, expect } from 'vitest'
+import { normalize, isConfidentMatch, candidateAlbums } from '../src/matcher.js'
+
+describe('normalize', () => {
+  it('lowercases, strips punctuation, articles, accents, extra whitespace', () => {
+    expect(normalize('The Cinematic Orchestra!')).toBe('cinematic orchestra')
+    expect(normalize('  Blur: The Best   of… ')).toBe('blur best of')
+    expect(normalize('Björk — Début')).toBe('bjork debut')
+    expect(normalize('A Tribe Called Quest')).toBe('tribe called quest')
+  })
+})
+
+describe('isConfidentMatch', () => {
+  it('matches when normalized artist AND title are equal', () => {
+    expect(
+      isConfidentMatch(
+        { title: 'Motion!', artist: 'The Cinematic Orchestra' },
+        { title: 'Motion', artist: 'Cinematic Orchestra' }
+      )
+    ).toBe(true)
+    expect(
+      isConfidentMatch(
+        { title: 'Motion', artist: 'Massive Attack' },
+        { title: 'Motion', artist: 'The Cinematic Orchestra' }
+      )
+    ).toBe(false)
+    expect(
+      isConfidentMatch(
+        { title: 'Blue Lines', artist: 'Massive Attack' },
+        { title: 'Motion', artist: 'Massive Attack' }
+      )
+    ).toBe(false)
+  })
+})
+
+describe('candidateAlbums', () => {
+  const albums = [
+    { id: 1, title: 'Motion', artist: 'Someone Else' },
+    { id: 2, title: 'Motion', artist: 'The Cinematic Orchestra' },
+    { id: 3, title: 'Other Album', artist: 'The Cinematic Orchestra' },
+  ]
+
+  it('returns same-title albums with artist matches first', () => {
+    const candidates = candidateAlbums(
+      { title: 'Motion', artist: 'Cinematic Orchestra' },
+      albums
+    )
+    expect(candidates.map((c) => c.id)).toEqual([2, 1])
+  })
+
+  it('caps candidates at 20', () => {
+    const many = Array.from({ length: 50 }, (_, i) => ({
+      id: i,
+      title: 'Motion',
+      artist: `Artist ${i}`,
+    }))
+    expect(candidateAlbums({ title: 'Motion', artist: 'zzz' }, many)).toHaveLength(20)
+  })
+})