feat(server/m7-352): system mix helpers (tieBreakHash, pickSeedArtists)

2026-05-04 08:24:39 -04:00
parent d7aebafa5d
commit ef478778ef
3 changed files with 147 additions and 0 deletions
@@ -0,0 +1,33 @@
+package playlists
+
+import (
+	"testing"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+func TestTieBreakHash_Deterministic(t *testing.T) {
+	id := pgtype.UUID{Bytes: [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, Valid: true}
+	a := tieBreakHash(id, "2026-05-04")
+	b := tieBreakHash(id, "2026-05-04")
+	if a != b {
+		t.Fatalf("same inputs gave different hashes: %d vs %d", a, b)
+	}
+}
+
+func TestTieBreakHash_DifferentDateChangesHash(t *testing.T) {
+	id := pgtype.UUID{Bytes: [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, Valid: true}
+	may4 := tieBreakHash(id, "2026-05-04")
+	may5 := tieBreakHash(id, "2026-05-05")
+	if may4 == may5 {
+		t.Errorf("different dates should change hash; got %d for both", may4)
+	}
+}
+
+func TestTieBreakHash_DifferentTrackChangesHash(t *testing.T) {
+	a := pgtype.UUID{Bytes: [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, Valid: true}
+	b := pgtype.UUID{Bytes: [16]byte{16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1}, Valid: true}
+	if tieBreakHash(a, "2026-05-04") == tieBreakHash(b, "2026-05-04") {
+		t.Errorf("different track ids should change hash for the same date")
+	}
+}