2 files changed, 48 insertions, 18 deletions

diff --git a/extensions/web/13_message_port.js b/extensions/web/13_message_port.js
index d111b5e01..d5014fdb9 100644
--- a/extensions/web/13_message_port.js
+++ b/extensions/web/13_message_port.js
@@ -89,7 +89,7 @@
 
     /**
      * @param {any} message
-     * @param {object[] | PostMessageOptions} transferOrOptions
+     * @param {object[] | StructuredSerializeOptions} transferOrOptions
      */
     postMessage(message, transferOrOptions = {}) {
       webidl.assertBranded(this, MessagePort);
@@ -108,10 +108,13 @@
         );
         options = { transfer };
       } else {
-        options = webidl.converters.PostMessageOptions(transferOrOptions, {
-          prefix,
-          context: "Argument 2",
-        });
+        options = webidl.converters.StructuredSerializeOptions(
+          transferOrOptions,
+          {
+            prefix,
+            context: "Argument 2",
+          },
+        );
       }
       const { transfer } = options;
       if (transfer.includes(this)) {
@@ -247,23 +250,37 @@
     };
   }
 
-  webidl.converters.PostMessageOptions = webidl.createDictionaryConverter(
-    "PostMessageOptions",
-    [
-      {
-        key: "transfer",
-        converter: webidl.converters["sequence<object>"],
-        get defaultValue() {
-          return [];
+  webidl.converters.StructuredSerializeOptions = webidl
+    .createDictionaryConverter(
+      "StructuredSerializeOptions",
+      [
+        {
+          key: "transfer",
+          converter: webidl.converters["sequence<object>"],
+          get defaultValue() {
+            return [];
+          },
         },
-      },
-    ],
-  );
+      ],
+    );
+
+  function structuredClone(value, options) {
+    const prefix = "Failed to execute 'structuredClone'";
+    webidl.requiredArguments(arguments.length, 1, { prefix });
+    options = webidl.converters.StructuredSerializeOptions(options, {
+      prefix,
+      context: "Argument 2",
+    });
+    const messageData = serializeJsMessageData(value, options.transfer);
+    const [data] = deserializeJsMessageData(messageData);
+    return data;
+  }
 
   window.__bootstrap.messagePort = {
     MessageChannel,
     MessagePort,
     deserializeJsMessageData,
     serializeJsMessageData,
+    structuredClone,
   };
 })(globalThis);
diff --git a/extensions/web/lib.deno_web.d.ts b/extensions/web/lib.deno_web.d.ts
index 6c79f61bd..3f110353f 100644
--- a/extensions/web/lib.deno_web.d.ts
+++ b/extensions/web/lib.deno_web.d.ts
@@ -673,7 +673,15 @@ declare class MessageEvent<T = any> extends Event {
 
 type Transferable = ArrayBuffer | MessagePort;
 
-interface PostMessageOptions {
+/**
+ * @deprecated
+ *
+ * This type has been renamed to StructuredSerializeOptions. Use that type for
+ * new code.
+ */
+type PostMessageOptions = StructuredSerializeOptions;
+
+interface StructuredSerializeOptions {
   transfer?: Transferable[];
 }
 
@@ -710,7 +718,7 @@ declare class MessagePort extends EventTarget {
    * objects or port, or if message could not be cloned.
    */
   postMessage(message: any, transfer: Transferable[]): void;
-  postMessage(message: any, options?: PostMessageOptions): void;
+  postMessage(message: any, options?: StructuredSerializeOptions): void;
   /**
    * Begins dispatching messages received on the port. This is implictly called
    * when assiging a value to `this.onmessage`.
@@ -737,3 +745,8 @@ declare class MessagePort extends EventTarget {
     options?: boolean | EventListenerOptions,
   ): void;
 }
+
+declare function structuredClone(
+  value: any,
+  options?: StructuredSerializeOptions,
+): any;