test(api): end-to-end contextual ranking test for /api/radio

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/api/library_fixtures_test.go

@@ -89,6 +89,72 @@ func seedTrack(t *testing.T, pool *pgxpool.Pool, albumID, artistID pgtype.UUID,
 	return tr
 }
 
+// seedTrackWithGenre is seedTrack but lets the caller set Genre. Used by
+// tests that exercise the contextual recommendation path, since session
+// vectors collect tags from tracks.genre.
+func seedTrackWithGenre(t *testing.T, pool *pgxpool.Pool, albumID, artistID pgtype.UUID, title string, trackNumber int, durationMs int32, genre string) dbq.Track {
+	t.Helper()
+	var tn *int32
+	if trackNumber > 0 {
+		v := int32(trackNumber)
+		tn = &v
+	}
+	tr, err := dbq.New(pool).UpsertTrack(context.Background(), dbq.UpsertTrackParams{
+		Title:       title,
+		AlbumID:     albumID,
+		ArtistID:    artistID,
+		TrackNumber: tn,
+		DiscNumber:  nil,
+		DurationMs:  durationMs,
+		FilePath:    "/seed/" + title + ".flac",
+		FileSize:    1024,
+		FileFormat:  "flac",
+		Bitrate:     nil,
+		Mbid:        nil,
+		Genre:       &genre,
+	})
+	if err != nil {
+		t.Fatalf("UpsertTrack(%s): %v", title, err)
+	}
+	return tr
+}
+
+// insertOpenSessionWithVector creates a play_session with ended_at NULL and
+// inserts a play_event in it whose session_vector_at_play is the given JSON.
+// Used to simulate "user is mid-listen" for the radio handler's current-vector
+// lookup. The play_event references a placeholder track inserted on the fly
+// so the FK is valid; the placeholder is not used for radio scoring.
+func insertOpenSessionWithVector(t *testing.T, pool *pgxpool.Pool, userID, anyArtistID pgtype.UUID, vectorJSON []byte) {
+	t.Helper()
+	q := dbq.New(pool)
+	al, err := q.UpsertAlbum(context.Background(), dbq.UpsertAlbumParams{
+		Title: "PlaceholderAlbum", SortTitle: "PlaceholderAlbum", ArtistID: anyArtistID,
+	})
+	if err != nil {
+		t.Fatalf("placeholder album: %v", err)
+	}
+	ph, err := q.UpsertTrack(context.Background(), dbq.UpsertTrackParams{
+		Title: "Placeholder", AlbumID: al.ID, ArtistID: anyArtistID,
+		FilePath: "/seed/placeholder.flac", DurationMs: 100_000, FileSize: 1024, FileFormat: "flac",
+	})
+	if err != nil {
+		t.Fatalf("placeholder track: %v", err)
+	}
+	var sessionID pgtype.UUID
+	if err := pool.QueryRow(context.Background(),
+		`INSERT INTO play_sessions (user_id, started_at, last_event_at, client_id)
+		 VALUES ($1, now() - interval '5 minutes', now(), 'test') RETURNING id`,
+		userID).Scan(&sessionID); err != nil {
+		t.Fatalf("insert session: %v", err)
+	}
+	if _, err := pool.Exec(context.Background(),
+		`INSERT INTO play_events (user_id, track_id, session_id, started_at, session_vector_at_play)
+		 VALUES ($1, $2, $3, now() - interval '1 minute', $4)`,
+		userID, ph.ID, sessionID, vectorJSON); err != nil {
+		t.Fatalf("insert play_event: %v", err)
+	}
+}
+
 // seedTrackWithFile creates a fresh temp directory, writes fileBody to
 // <dir>/<title>.<ext>, and inserts a Track row whose file_path points at it.
 // Returns the inserted Track and the directory (callers drop sidecar covers