check URLSearchParams.constructor's params (#2488)

js/url_search_params.ts

@@ -280,11 +280,11 @@ export class URLSearchParams {
     // Overload: sequence<sequence<USVString>>
     for (const tuple of init) {
       // If pair does not contain exactly two items, then throw a TypeError.
-      requiredArguments(
+      if (tuple.length !== 2) {
-        "URLSearchParams.constructor tuple array argument",
+        throw new TypeError(
-        tuple.length,
+          "URLSearchParams.constructor tuple array argument must only contain pair elements"
-        2
         );
+      }
       this.append(tuple[0], tuple[1]);
     }
   }

js/url_search_params_test.ts

@@ -147,6 +147,19 @@ test(function urlSearchParamsShouldThrowTypeError(): void {
   }
 
   assertEquals(hasThrown, 2);
+
+  try {
+    new URLSearchParams([["1", "2", "3"]]);
+    hasThrown = 1;
+  } catch (err) {
+    if (err instanceof TypeError) {
+      hasThrown = 2;
+    } else {
+      hasThrown = 3;
+    }
+  }
+
+  assertEquals(hasThrown, 2);
 });
 
 test(function urlSearchParamsAppendArgumentsCheck(): void {