1 files changed, 70 insertions, 0 deletions
diff --git a/extensions/web/04_global_interfaces.js b/extensions/web/04_global_interfaces.js
new file mode 100644
index 000000000..c3181fb66
--- /dev/null
+++ b/extensions/web/04_global_interfaces.js
@@ -0,0 +1,70 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+"use strict";
+((window) => {
+  const { EventTarget } = window;
+
+  const illegalConstructorKey = Symbol("illegalConstructorKey");
+
+  class Window extends EventTarget {
+    constructor(key = null) {
+      if (key !== illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+      super();
+    }
+
+    get [Symbol.toStringTag]() {
+      return "Window";
+    }
+  }
+
+  class WorkerGlobalScope extends EventTarget {
+    constructor(key = null) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+      super();
+    }
+
+    get [Symbol.toStringTag]() {
+      return "WorkerGlobalScope";
+    }
+  }
+
+  class DedicatedWorkerGlobalScope extends WorkerGlobalScope {
+    constructor(key = null) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+      super();
+    }
+
+    get [Symbol.toStringTag]() {
+      return "DedicatedWorkerGlobalScope";
+    }
+  }
+
+  window.__bootstrap.globalInterfaces = {
+    DedicatedWorkerGlobalScope,
+    Window,
+    WorkerGlobalScope,
+    dedicatedWorkerGlobalScopeConstructorDescriptor: {
+      configurable: true,
+      enumerable: false,
+      value: DedicatedWorkerGlobalScope,
+      writable: true,
+    },
+    windowConstructorDescriptor: {
+      configurable: true,
+      enumerable: false,
+      value: Window,
+      writable: true,
+    },
+    workerGlobalScopeConstructorDescriptor: {
+      configurable: true,
+      enumerable: false,
+      value: WorkerGlobalScope,
+      writable: true,
+    },
+  };
+})(this);