Merge pull request #995 from capricorn86/task/992-typeerror-cannot-re…

…ad-properties-of-undefined-reading-write

#992@patch: Fixes problem where HTMLIFrameElement fails to load page …

packages/happy-dom/src/nodes/document/Document.ts

@@ -56,13 +56,15 @@ const PROCESSING_INSTRUCTION_TARGET_REGEXP = /^[a-z][a-z0-9-]+$/;
  */
 export default class Document extends Node implements IDocument {
 	public static _defaultView: IWindow = null;
+	public static _windowClass: {} | null = null;
 	public nodeType = Node.DOCUMENT_NODE;
 	public adoptedStyleSheets: CSSStyleSheet[] = [];
 	public implementation: DOMImplementation;
 	public readonly children: IHTMLCollection<IElement> = new HTMLCollection<IElement>();
 	public readonly readyState = DocumentReadyStateEnum.interactive;
 	public readonly isConnected: boolean = true;
 	public readonly defaultView: IWindow;
+	public readonly _windowClass: {} | null = null;
 	public readonly _readyStateManager: DocumentReadyStateManager;
 	public _activeElement: IHTMLElement = null;
 
@@ -197,6 +199,7 @@ export default class Document extends Node implements IDocument {
 		this.defaultView = (<typeof Document>this.constructor)._defaultView;
 		this.implementation = new DOMImplementation(this);
 
+		this._windowClass = (<typeof Document>this.constructor)._windowClass;
 		this._readyStateManager = new DocumentReadyStateManager(this.defaultView);
 		this._rootNode = this;
 

packages/happy-dom/src/nodes/html-iframe-element/HTMLIFrameUtility.ts

@@ -2,7 +2,6 @@ import { URL } from 'url';
 import Event from '../../event/Event.js';
 import ErrorEvent from '../../event/events/ErrorEvent.js';
 import IWindow from '../../window/IWindow.js';
-import Window from '../../window/Window.js';
 import IFrameCrossOriginWindow from './IFrameCrossOriginWindow.js';
 import HTMLIFrameElement from './HTMLIFrameElement.js';
 
@@ -23,7 +22,8 @@ export default class HTMLIFrameUtility {
 			const src = element.src;
 
 			if (src) {
-				const contentWindow = new (<typeof Window>element.ownerDocument.defaultView.constructor)({
+				// To avoid circular dependency, we use a reference to the window class instead of importing it.
+				const contentWindow = <IWindow>new element.ownerDocument['_windowClass']({
 					url: src,
 					settings: {
 						...element.ownerDocument.defaultView.happyDOM.settings

packages/happy-dom/src/window/Window.ts

@@ -519,6 +519,7 @@ export default class Window extends EventTarget implements IWindow {
 		}
 
 		HTMLDocument._defaultView = this;
+		HTMLDocument._windowClass = Window;
 
 		const document = new HTMLDocument();