fix: sync removes albums no longer in subsonic, classify non-json responses as api errors

server/src/subsonic.ts

@@ -55,8 +55,11 @@ export class SubsonicClient {
       throw new SubsonicError('unreachable', `could not reach ${this.base}`)
     }
     if (!res.ok) throw new SubsonicError('unreachable', `HTTP ${res.status} from ${this.base}`)
-    const body = (await res.json()) as {
+    let body: any
-      'subsonic-response'?: { status?: string; error?: { code?: number; message?: string } }
+    try {
+      body = await res.json()
+    } catch {
+      throw new SubsonicError('api', 'malformed subsonic response')
     }
     const envelope = body['subsonic-response']
     if (!envelope) throw new SubsonicError('api', 'malformed subsonic response')

server/src/sync.ts

@@ -40,14 +40,20 @@ export class SyncManager {
     const client = new SubsonicClient({ ...config, fetchImpl: this.fetchImpl })
     try {
       const albums = await client.getAllAlbums()
+      const seenIds = new Set(albums.map((a) => a.id))
       const upsert = this.db.prepare(
         `INSERT INTO digital_albums (user_id, subsonic_id, title, artist) VALUES (?, ?, ?, ?)
          ON CONFLICT(user_id, subsonic_id) DO UPDATE SET title = excluded.title, artist = excluded.artist`
       )
-      const insertAll = this.db.transaction((rows: { id: string; title: string; artist: string }[]) => {
+      const selectAll = this.db.prepare('SELECT id, subsonic_id FROM digital_albums WHERE user_id = ?')
-        for (const r of rows) upsert.run(userId, r.id, r.title, r.artist)
+      const deleteById = this.db.prepare('DELETE FROM digital_albums WHERE id = ?')
+      const apply = this.db.transaction(() => {
+        for (const r of albums) upsert.run(userId, r.id, r.title, r.artist)
+        for (const row of selectAll.all(userId) as { id: number; subsonic_id: string }[]) {
+          if (!seenIds.has(row.subsonic_id)) deleteById.run(row.id)
+        }
       })
-      insertAll(albums)
+      apply()
       this.states.set(userId, {
         status: 'done',
         error: null,

server/test/library.test.ts

@@ -154,4 +154,53 @@ describe('library sync', () => {
     expect(state.albums).toBe(503)
     await app.close()
   })
+
+  it('re-sync removes albums that disappeared from subsonic', async () => {
+    // sync 1 (from settings PUT): 1 album 'Kept Album'
+    // sync 2 (explicit POST): 1 album 'Only Album' — 'Kept Album' must be gone
+    let syncCount = 0
+    const shrinking = (async (input: any) => {
+      const url = new URL(String(input))
+      if (url.pathname.endsWith('/rest/ping')) {
+        return new Response(JSON.stringify({ 'subsonic-response': { status: 'ok' } }), {
+          status: 200,
+          headers: { 'content-type': 'application/json' },
+        })
+      }
+      if (url.pathname.endsWith('/rest/getAlbumList2')) {
+        syncCount++
+        const album =
+          syncCount === 1
+            ? { id: 1, name: 'Kept Album', artist: 'Artist A' }
+            : { id: 9, name: 'Only Album', artist: 'Artist B' }
+        return new Response(
+          JSON.stringify({ 'subsonic-response': { status: 'ok', albumList2: { album: [album] } } }),
+          { status: 200, headers: { 'content-type': 'application/json' } }
+        )
+      }
+      return new Response('nope', { status: 404 })
+    }) as typeof fetch
+    const app = await buildTestApp(shrinking)
+    const cookie = await setupAdmin(app)
+    await app.inject({
+      method: 'PUT',
+      url: '/api/settings',
+      ...auth(cookie),
+      payload: { subsonicUrl: 'http://n.local', subsonicUsername: 'sam', subsonicPassword: 'pass' },
+    })
+
+    const first = await waitForDone(app, cookie)
+    expect(first.albums).toBe(1)
+    expect(await app.inject({ method: 'GET', url: '/api/library/albums?q=Kept', ...auth(cookie) }).then((r) => r.json())).toMatchObject({ albums: [expect.objectContaining({ title: 'Kept Album' })] })
+
+    await app.inject({ method: 'POST', url: '/api/library/sync', ...auth(cookie) })
+    const second = await waitForDone(app, cookie)
+    expect(second.albums).toBe(1)
+
+    const stale = await app.inject({ method: 'GET', url: '/api/library/albums?q=Kept', ...auth(cookie) })
+    expect(stale.json().albums).toHaveLength(0) // stale album removed
+    const kept = await app.inject({ method: 'GET', url: '/api/library/albums?q=Only', ...auth(cookie) })
+    expect(kept.json().albums).toHaveLength(1)
+    await app.close()
+  })
 })