fix: Dedupe track collaborators in API responses

api/dbv1/tracks.go

@@ -50,6 +50,7 @@ func (q *Queries) TracksKeyed(ctx context.Context, arg TracksParams) (map[int32]
 
 	userIds := []int32{}
 	trackIds := make([]int32, 0, len(rawTracks))
+	ownerByTrack := make(map[int32]int32, len(rawTracks))
 	collectSplitUserIds := func(usage *AccessGate) {
 		if usage == nil || usage.UsdcPurchase == nil {
 			return
@@ -62,6 +63,7 @@ func (q *Queries) TracksKeyed(ctx context.Context, arg TracksParams) (map[int32]
 	for _, rawTrack := range rawTracks {
 		userIds = append(userIds, rawTrack.UserID)
 		trackIds = append(trackIds, rawTrack.TrackID)
+		ownerByTrack[rawTrack.TrackID] = rawTrack.UserID
 
 		var remixOf RemixOf
 		json.Unmarshal(rawTrack.RemixOf, &remixOf)
@@ -169,15 +171,15 @@ func (q *Queries) TracksKeyed(ctx context.Context, arg TracksParams) (map[int32]
 
 		// Resolve accepted collaborators (order preserved from the query).
 		collaborators := []User{}
-		for _, cid := range collaboratorsByTrack[rawTrack.TrackID] {
+		for _, cid := range uniqueCollaboratorIDs(collaboratorsByTrack[rawTrack.TrackID], ownerByTrack[rawTrack.TrackID]) {
 			if cu, ok := userMap[cid]; ok {
 				collaborators = append(collaborators, cu)
 			}
 		}
 
 		// Resolve pending collaborators (only present for the owner's own tracks).
 		pendingCollaborators := []User{}
-		for _, cid := range pendingByTrack[rawTrack.TrackID] {
+		for _, cid := range uniqueCollaboratorIDs(pendingByTrack[rawTrack.TrackID], ownerByTrack[rawTrack.TrackID]) {
 			if cu, ok := userMap[cid]; ok {
 				pendingCollaborators = append(pendingCollaborators, cu)
 			}
@@ -264,3 +266,20 @@ func (q *Queries) Tracks(ctx context.Context, arg TracksParams) ([]Track, error)
 
 	return tracks, nil
 }
+
+func uniqueCollaboratorIDs(collaboratorIDs []int32, ownerID int32) []int32 {
+	if len(collaboratorIDs) == 0 {
+		return nil
+	}
+
+	seen := map[int32]struct{}{ownerID: {}}
+	uniqueIDs := make([]int32, 0, len(collaboratorIDs))
+	for _, collaboratorID := range collaboratorIDs {
+		if _, ok := seen[collaboratorID]; ok {
+			continue
+		}
+		seen[collaboratorID] = struct{}{}
+		uniqueIDs = append(uniqueIDs, collaboratorID)
+	}
+	return uniqueIDs
+}

api/dbv1/tracks_test.go

@@ -0,0 +1,16 @@
+package dbv1
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestUniqueCollaboratorIDs(t *testing.T) {
+	assert.Equal(
+		t,
+		[]int32{2, 3, 4},
+		uniqueCollaboratorIDs([]int32{2, 2, 1, 3, 3, 4}, 1),
+	)
+	assert.Nil(t, uniqueCollaboratorIDs(nil, 1))
+}

api/v1_track_collaborators_test.go

@@ -31,6 +31,10 @@ func seedCollaborators(t *testing.T, app *ApiServer) {
 func TestTrackCollaboratorsEmbeddedOnTrack(t *testing.T) {
 	app := testAppWithFixtures(t)
 	seedCollaborators(t, app)
+	now := time.Now()
+	database.SeedTable(app.pool.Replicas[0], "track_collaborators", []map[string]any{
+		{"track_id": 700, "collaborator_user_id": 500, "invited_by": 500, "status": "accepted", "created_at": now, "updated_at": now},
+	})
 
 	var resp struct {
 		Data []dbv1.Track
@@ -42,6 +46,7 @@ func TestTrackCollaboratorsEmbeddedOnTrack(t *testing.T) {
 		"data.3.id":                     trashid.MustEncodeHashID(700),
 		"data.3.collaborators.0.handle": "rayjacobson",
 	})
+	assert.Len(t, resp.Data[3].Collaborators, 1, "owner should not be embedded as their own collaborator")
 	// Non-collaborated tracks carry an empty array, not null.
 	assert.Contains(t, string(body), `"collaborators":[]`)
 }