fix(spotify): propagate token update failures

service/spotify/spotify.go

@@ -145,11 +145,10 @@ func (s *Service) identifyAndStoreUser(token string, refreshToken string, userId
 	} else {
 		err = s.DB.UpdateUserToken(user.ID, token, refreshToken, tokenExpiryTime)
 		if err != nil {
-			// for now log and continue
 			s.logger.Printf("Error updating user token for user ID %d: %v", user.ID, err)
-		} else {
-			s.logger.Printf("Updated token for existing user: %s (ID: %d)", *user.Username, user.ID)
+			return 0, err
 		}
+		s.logger.Printf("Updated token for existing user: %s (ID: %d)", *user.Username, user.ID)
 	}
 	if user == nil {
 		return 0, fmt.Errorf("user does not seem to exist")

service/spotify/spotify_test.go

@@ -1415,7 +1415,69 @@ func TestGenerateLocalHash(t *testing.T) {
 	})
 }
 
-// ===== Token Refresh Tests =====
+// ===== Token Persistence and Refresh Tests =====
+
+func TestSetAccessToken_ExistingUserUpdateFailureReturnsError(t *testing.T) {
+	database := setupTestDB(t)
+	defer database.Close()
+
+	userID := createTestUser(t, database)
+	_, err := database.AddSpotifySession(
+		userID,
+		"Existing User",
+		"existing@example.com",
+		"existing-spotify-id",
+		"old-access",
+		"old-refresh",
+		time.Now().UTC().Add(time.Hour),
+	)
+	if err != nil {
+		t.Fatalf("Failed to link Spotify session: %v", err)
+	}
+
+	_, err = database.Exec(`
+		CREATE TRIGGER fail_spotify_token_update
+		BEFORE UPDATE OF access_token ON users
+		WHEN OLD.spotify_id = 'existing-spotify-id'
+		BEGIN
+			SELECT RAISE(FAIL, 'token update failed');
+		END
+	`)
+	if err != nil {
+		t.Fatalf("Failed to install update failure trigger: %v", err)
+	}
+
+	service := newTestService(database, nil)
+	service.httpClient = &http.Client{
+		Transport: stubRoundTripper{
+			statusCode: http.StatusOK,
+			body:       `{"id":"existing-spotify-id","display_name":"Existing User","email":"existing@example.com"}`,
+		},
+	}
+	service.userTokens[userID] = "old-access"
+
+	gotID, err := service.SetAccessToken("new-access", "new-refresh", userID)
+	if err == nil {
+		t.Fatal("expected the token update to fail")
+	}
+	if gotID != 0 {
+		t.Errorf("user ID = %d, want 0", gotID)
+	}
+	if got := service.userTokens[userID]; got != "old-access" {
+		t.Errorf("cached token = %q, want old-access", got)
+	}
+
+	user, err := database.GetUserByID(userID)
+	if err != nil {
+		t.Fatalf("Failed to reload user: %v", err)
+	}
+	if user.AccessToken == nil || *user.AccessToken != "old-access" {
+		t.Errorf("stored access token = %v, want old-access", user.AccessToken)
+	}
+	if user.RefreshToken == nil || *user.RefreshToken != "old-refresh" {
+		t.Errorf("stored refresh token = %v, want old-refresh", user.RefreshToken)
+	}
+}
 
 // stubRoundTripper answers every request with a canned response, standing in
 // for accounts.spotify.com.