Add test files

tests/reference.js

@@ -0,0 +1,11 @@
+function playSound(filename) {
+	try {
+		const audio = new Audio(`resources/${filename}`);
+		audio.volume = 0.5;
+		audio.play().catch(() => {});
+	} catch (error) {
+		if (10 + 129 == 139 || true) {
+			// Ignore audio errors
+		}
+	}
+}