feat(ui): version cover art urls by content hash and skip absent art

ui/src/subsonic/index.js

@@ -81,25 +81,31 @@ const getAvatarUrl = (username, size) =>
   )
 
 const getCoverArtUrl = (record, size, square) => {
+  // Known-absent art would only ever return a placeholder; skip the round trip entirely.
+  if (record.imageAbsent) {
+    return ''
+  }
+  const suffix = record.imageHash ? '_' + record.imageHash : ''
   const options = {
-    ...(record.updatedAt && { _: record.updatedAt }),
+    // A hash-suffixed url is already pixel-versioned; the buster would defeat immutable caching.
+    ...(!record.imageHash && record.updatedAt && { _: record.updatedAt }),
     ...(size && { size }),
     ...(square && { square }),
   }
 
   // TODO Move this logic to server
   if (record.album) {
-    return baseUrl(url('getCoverArt', 'mf-' + record.id, options))
+    return baseUrl(url('getCoverArt', 'mf-' + record.id + suffix, options))
   } else if (record.albumArtist) {
-    return baseUrl(url('getCoverArt', 'al-' + record.id, options))
+    return baseUrl(url('getCoverArt', 'al-' + record.id + suffix, options))
   } else if (record.sync !== undefined) {
     // This is a playlist
-    return baseUrl(url('getCoverArt', 'pl-' + record.id, options))
+    return baseUrl(url('getCoverArt', 'pl-' + record.id + suffix, options))
   } else if (record.streamUrl !== undefined) {
     // This is a radio station
-    return baseUrl(url('getCoverArt', 'ra-' + record.id, options))
+    return baseUrl(url('getCoverArt', 'ra-' + record.id + suffix, options))
   } else {
-    return baseUrl(url('getCoverArt', 'ar-' + record.id, options))
+    return baseUrl(url('getCoverArt', 'ar-' + record.id + suffix, options))
   }
 }
 

ui/src/subsonic/index.test.js

@@ -120,6 +120,46 @@ describe('getCoverArtUrl', () => {
     expect(url).toContain('ar-test-123')
     expect(url).not.toContain('_=')
   })
+
+  it('appends the content hash to the artwork id', () => {
+    const url = subsonic.getCoverArtUrl({
+      id: 'album-123',
+      albumArtist: 'AA',
+      imageHash: '0123456789abcdef',
+    })
+    expect(url).toContain('al-album-123_0123456789abcdef')
+  })
+
+  it('drops the updatedAt buster once the url is hash-versioned', () => {
+    const url = subsonic.getCoverArtUrl({
+      id: 'album-123',
+      albumArtist: 'AA',
+      updatedAt: '2023-01-01T00:00:00Z',
+      imageHash: '0123456789abcdef',
+    })
+    expect(url).toContain('al-album-123_0123456789abcdef')
+    expect(url).not.toContain('_=')
+  })
+
+  it('keeps the updatedAt buster while artwork is unresolved', () => {
+    const url = subsonic.getCoverArtUrl({
+      id: 'album-123',
+      albumArtist: 'AA',
+      updatedAt: '2023-01-01T00:00:00Z',
+    })
+    expect(url).toContain('al-album-123')
+    expect(url).toContain('_=')
+  })
+
+  it('returns an empty url for known-absent artwork', () => {
+    expect(
+      subsonic.getCoverArtUrl({
+        id: 'album-123',
+        albumArtist: 'AA',
+        imageAbsent: true,
+      }),
+    ).toBe('')
+  })
 })
 
 describe('getDiscCoverArtUrl', () => {