2 files changed, 16 insertions, 1 deletions
diff --git a/js/url_search_params.ts b/js/url_search_params.ts
index 1b4461ed2..9f4621b7b 100644
--- a/js/url_search_params.ts
+++ b/js/url_search_params.ts
@@ -32,7 +32,7 @@ export class URLSearchParams {
    */
   append(name: string, value: string): void {
     requiredArguments("URLSearchParams.append", arguments.length, 2);
-    this.params.push([String(name), value]);
+    this.params.push([String(name), String(value)]);
   }
 
   /** Deletes the given search parameter and its associated value,
@@ -112,6 +112,7 @@ export class URLSearchParams {
     // set the value of the first such name-value pair to value
     // and remove the others.
     name = String(name);
+    value = String(value);
     let found = false;
     let i = 0;
     while (i < this.params.length) {
diff --git a/js/url_search_params_test.ts b/js/url_search_params_test.ts
index 9b20b3b75..8da11382f 100644
--- a/js/url_search_params_test.ts
+++ b/js/url_search_params_test.ts
@@ -182,3 +182,17 @@ test(function urlSearchParamsAppendArgumentsCheck(): void {
     }
   );
 });
+
+// ref: https://github.com/web-platform-tests/wpt/blob/master/url/urlsearchparams-delete.any.js
+test(function urlSearchParamsDeletingAppendedMultiple(): void {
+  const params = new URLSearchParams();
+  params.append("first", (1 as unknown) as string);
+  assert(params.has("first"));
+  assertEquals(params.get("first"), "1");
+  params.delete("first");
+  assertEquals(params.has("first"), false);
+  params.append("first", (1 as unknown) as string);
+  params.append("first", (10 as unknown) as string);
+  params.delete("first");
+  assertEquals(params.has("first"), false);
+});