fix: prefer original over japanese in db displaytitle

internal/db/helpers_test.go

@@ -0,0 +1,30 @@
+package db
+
+import (
+	"database/sql"
+	"testing"
+)
+
+func TestDisplayTitlePrefersOriginalBeforeJapanese(t *testing.T) {
+	got := DisplayTitle(
+		sql.NullString{},
+		sql.NullString{String: "サイバーパンク エッジランナーズ", Valid: true},
+		"Cyberpunk: Edgerunners",
+	)
+
+	if got != "Cyberpunk: Edgerunners" {
+		t.Fatalf("DisplayTitle() = %q, want original title", got)
+	}
+}
+
+func TestDisplayTitlePrefersEnglish(t *testing.T) {
+	got := DisplayTitle(
+		sql.NullString{String: "Frieren: Beyond Journey's End", Valid: true},
+		sql.NullString{String: "葬送のフリーレン", Valid: true},
+		"Sousou no Frieren",
+	)
+
+	if got != "Frieren: Beyond Journey's End" {
+		t.Fatalf("DisplayTitle() = %q, want English title", got)
+	}
+}