streamer/queue: make queue return copies of entries (fixes #145)

radio: add Song.Copy and QueueEntry.Copy

radio.go

@@ -460,6 +460,11 @@ type QueueEntry struct {
 	ExpectedStartTime time.Time
 }
 
+func (qe QueueEntry) Copy() QueueEntry {
+	qe.Song = qe.Song.Copy()
+	return qe
+}
+
 func (qe QueueEntry) String() string {
 	est := qe.ExpectedStartTime.Format("2006-01-02 15:04:05")
 	if qe.IsUserRequest {
@@ -679,6 +684,19 @@ type DatabaseTrack struct {
 	RequestCount int
 }
 
+// Copy copies the song and returns it
+func (s Song) Copy() Song {
+	if s.DatabaseTrack != nil {
+		dt := *s.DatabaseTrack
+		s.DatabaseTrack = &dt
+	}
+	if s.LastPlayedBy != nil {
+		lpb := *s.LastPlayedBy
+		s.LastPlayedBy = &lpb
+	}
+	return s
+}
+
 // Requestable returns whether this song can be requested by a user
 func (s *Song) Requestable() bool {
 	if s == nil || s.DatabaseTrack == nil {

radio_test.go

@@ -577,3 +577,35 @@ func TestSongHashJSON(t *testing.T) {
 	}))
 	p.TestingRun(t)
 }
+
+func TestSongCopy(t *testing.T) {
+	a := arbitrary.DefaultArbitraries()
+	p := gopter.NewProperties(nil)
+	p.Property("copy is equal", a.ForAll(func(in Song) bool {
+		out := in.Copy()
+
+		return reflect.DeepEqual(in, out)
+	}))
+	p.Property("copy is an actual copy", a.ForAll(func(in Song, in2 DatabaseTrack) bool {
+		in.DatabaseTrack = &in2
+
+		out := in.Copy()
+
+		out.TrackID = out.TrackID + 2000
+		out.Artist = out.Artist + "added artist"
+		out.Title = out.Title + "added title"
+		out.Album = out.Album + "added album"
+		out.FilePath = out.FilePath + "added filepath"
+		out.Tags = out.Tags + "added tags"
+		out.Acceptor = out.Acceptor + "added acceptor"
+		out.LastEditor = out.LastEditor + "added lasteditor"
+		out.Priority = out.Priority + 20
+		out.Usable = !out.Usable
+		out.NeedReplacement = !out.NeedReplacement
+		out.RequestCount = out.RequestCount + 5
+		out.LastRequested = out.LastRequested.Add(time.Minute * 4)
+
+		return !reflect.DeepEqual(in, out)
+	}))
+	p.TestingRun(t)
+}

streamer/queue.go

@@ -129,7 +129,7 @@ func (qs *QueueService) AddRequest(ctx context.Context, song radio.Song, identif
 	defer qs.mu.Unlock()
 
 	qs.append(ctx, radio.QueueEntry{
-		Song:           song,
+		Song:           song.Copy(),
 		IsUserRequest:  true,
 		UserIdentifier: identifier,
 	})
@@ -156,7 +156,7 @@ func (qs *QueueService) ReserveNext(ctx context.Context) (*radio.QueueEntry, err
 		return nil, errors.E(op, errors.QueueExhausted)
 	}
 
-	entry := qs.queue[qs.reservedIndex]
+	entry := qs.queue[qs.reservedIndex].Copy()
 	qs.reservedIndex++
 	qs.logger.Info().Str("entry", entry.String()).Msg("reserve in queue")
 
@@ -234,8 +234,10 @@ func (qs *QueueService) Entries(ctx context.Context) (radio.Queue, error) {
 	qs.mu.Lock()
 	defer qs.mu.Unlock()
 
-	all := make([]radio.QueueEntry, len(qs.queue))
-	copy(all, qs.queue)
+	all := make([]radio.QueueEntry, 0, len(qs.queue))
+	for _, e := range qs.queue {
+		all = append(all, e.Copy())
+	}
 	return all, nil
 }