Add a structuredClone() global

python/pythonmonkey/__init__.py

@@ -14,4 +14,5 @@
 require("base64")
 require("timers")
 require("url")
+require("structured-clone")
 require("XMLHttpRequest")

python/pythonmonkey/builtin_modules/structured-clone.js

@@ -0,0 +1,15 @@
+/**
+ * @file     structured-clone.js
+ *           Polyfill the structuredClone() global
+ *
+ * @author   Dan Desjardins <dan@distributive.network>
+ * @date     November 2026
+ *
+ * @copyright Copyright (c) 2026 Distributive Corp.
+ */
+
+// Apply polyfill from core-js
+require('./dom-exception');
+require('core-js/actual/structured-clone');
+
+exports.structuredClone = globalThis.structuredClone;

python/pythonmonkey/global.d.ts

@@ -64,6 +64,9 @@ declare var clearInterval: typeof import("timers").clearInterval;
 declare var URL: typeof import("url").URL;
 declare var URLSearchParams: typeof import("url").URLSearchParams;
 
+// Expose `structuredClone`
+declare function structuredClone<T = any>(value: T, options?: { transfer?: any[] }): T;
+
 // Expose `XMLHttpRequest` (XHR) API
 declare var XMLHttpRequest: typeof import("XMLHttpRequest").XMLHttpRequest;
 

tests/js/structured-clone.simple

@@ -0,0 +1,28 @@
+/**
+ * @file        structured-clone.simple
+ *              Simple test for the structuredClone() global
+ * @author      Dan Desjardins <dan@distributive.network>
+ * @date        November 2026
+ */
+
+function assert(cond, message)
+{
+  if (!cond) throw new Error(message);
+}
+
+assert(typeof structuredClone === 'function', 'structuredClone is not a global function');
+
+const source = { list: ['a'], nested: { map: new Map([[1, { x: 2 }]]), date: new Date(0), bytes: new Uint8Array([1, 2, 3]) } };
+source.self = source;
+const copy = structuredClone(source);
+
+copy.list.push('b');
+assert(source.list.length === 1, 'clone shares an array with its source');
+assert(copy.nested.map.get(1).x === 2, 'Map entries were not cloned');
+assert(copy.nested.date instanceof Date && copy.nested.date.getTime() === 0, 'Date was not cloned');
+assert(copy.nested.bytes.join() === '1,2,3' && copy.nested.bytes !== source.nested.bytes, 'Uint8Array was not cloned');
+assert(copy.self === copy, 'cycle was not preserved');
+
+let error;
+try { structuredClone(function f() {}); } catch (e) { error = e; }
+assert(error && error.name === 'DataCloneError', 'cloning a function did not throw DataCloneError');