Update WebviewExecutionService

app/components/Views/Wallet/WebviewExecutionService.ts

@@ -7,6 +7,10 @@ import {
   ExecutionServiceArgs,
 } from '@metamask/snap-controllers';
 import snapsState from '../../../core/SnapsState';
+// import SnapWebviewPostMessageStream from './SnapWebviewPostMessageStream';
+import { SnapDuplex } from './SnapDuplex';
+
+// const ObjectMultiplex = require('obj-multiplex');
 
 type IframeExecutionEnvironmentServiceArgs = {
   iframeUrl: URL;
@@ -27,13 +31,6 @@ export default class WebviewExecutionService extends AbstractExecutionService<Wi
     this.iframeUrl = iframeUrl;
   }
 
-  protected terminateJob(jobWrapper: Job<Window>): void {
-    // eslint-disable-next-line no-console
-    console.log('TERMINATE JOB----', jobWrapper);
-    // Send message to webview to remove certain iframe
-    //document.getElementById(jobWrapper.id)?.remove();
-  }
-
   protected async _initEnvStream(jobId: string): Promise<{
     worker;
     stream: BasePostMessageStream;
@@ -43,65 +40,19 @@ export default class WebviewExecutionService extends AbstractExecutionService<Wi
     const iframeWindow = snapsState.webview;
     const stream = snapsState.stream;
 
-    return { worker: iframeWindow, stream };
-  }
-
-  /**
-   * Creates the iframe to be used as the execution environment. This may run
-   * forever if the iframe never loads, but the promise should be wrapped in
-   * an initialization timeout in the SnapController.
-   *
-   * @param uri - The iframe URI.
-   * @param jobId - The job id.
-   * @returns A promise that resolves to the contentWindow of the iframe.
-   */
-  private async createWindow(uri: string, jobId: string): Promise<Window> {
-    return new Promise((resolve, reject) => {
-      const iframe = document.createElement('iframe');
-      // The order of operations appears to matter for everything except this
-      // attribute. We may as well set it here.
-      iframe.setAttribute('id', jobId);
-
-      // In the past, we've had problems that appear to be symptomatic of the
-      // iframe firing the `load` event before its scripts are actually loaded,
-      // which has prevented snaps from executing properly. Therefore, we set
-      // the `src` attribute and append the iframe to the DOM before attaching
-      // the `load` listener.
-      //
-      // `load` should only fire when "all dependent resources" have been
-      // loaded, which includes scripts.
-      //
-      // MDN article for `load` event: https://developer.mozilla.org/en-US/docs/Web/API/Window/load_event
-      // Re: `load` firing twice: https://stackoverflow.com/questions/10781880/dynamically-created-iframe-triggers-onload-event-twice/15880489#15880489
-      iframe.setAttribute('src', uri);
-      document.body.appendChild(iframe);
+    const snapStream = new SnapDuplex({
+      stream,
+      jobId,
+    });
 
-      iframe.addEventListener('load', () => {
-        if (iframe.contentWindow) {
-          resolve(iframe.contentWindow);
-        } else {
-          // We don't know of a case when this would happen, but better to fail
-          // fast if it does.
-          reject(
-            new Error(
-              `iframe.contentWindow not present on load for job "${jobId}".`,
-            ),
-          );
-        }
-      });
+    return { worker: iframeWindow, stream: snapStream };
+  }
 
-      // We need to set the sandbox attribute after appending the iframe to the
-      // DOM, otherwise errors in the iframe will not be propagated via `error`
-      // and `unhandledrejection` events, and we cannot catch and handle them.
-      // We wish we knew why this was the case.
-      //
-      // We set this property after adding the `load` listener because it
-      // appears to work dependably. ¯\_(ツ)_/¯
-      //
-      // We apply this property as a principle of least authority (POLA)
-      // measure.
-      // Ref: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#attr-sandbox
-      iframe.setAttribute('sandbox', 'allow-scripts');
-    });
+  protected _terminate(jobWrapper: Job<Window>): void {
+    // eslint-disable-next-line no-console
+    console.log(
+      'This method should a command to the WebView to teardown the iframe for the job with ID',
+      jobWrapper.id,
+    );
   }
 }