use the downloaded sim.html instead of hitting the live sim

package.json

@@ -361,8 +361,8 @@
   "dependencies": {
     "@types/path-browserify": "^1.0.0",
     "@vscode/extension-telemetry": "^0.7.5",
-    "makecode-browser": "^1.2.1",
-    "makecode-core": "^1.4.3",
+    "makecode-browser": "^1.3.1",
+    "makecode-core": "^1.7.0",
     "path-browserify": "^1.0.1"
   }
 }

src/web/makecodeOperations.ts

@@ -68,6 +68,10 @@ export function addDependencyAsync(folder: vscode.WorkspaceFolder, repo: string,
     return enqueueOperationAsync(folder, () => cmd.addCommand(repo, undefined as any /* the name is optional */, {}), cancellationToken);
 }
 
+export function getSimHtmlAsync(folder: vscode.WorkspaceFolder, cancellationToken?: vscode.CancellationToken) {
+    return enqueueOperationAsync(folder, () => cmd.getSimHTML({}), cancellationToken);
+}
+
 /**
  * The mkc CLI uses global state, so we need to perform operations in a queue just in case the
  * user is doing things in multiple workspaces at once

src/web/simulator.ts

@@ -1,8 +1,9 @@
 import * as vscode from "vscode";
 
 import { simloaderFiles } from "makecode-core/built/simloaderfiles";
-import { existsAsync, readFileAsync } from "./host";
+import { activeWorkspace, existsAsync, readFileAsync } from "./host";
 import { simulateCommand } from "./extension";
+import { getSimHtmlAsync } from "./makecodeOperations";
 
 let extensionContext: vscode.ExtensionContext;
 
@@ -54,6 +55,7 @@ export class Simulator {
 
     protected panel: vscode.WebviewPanel;
     protected binaryJS: string | undefined;
+    protected simHtml: string | undefined;
     protected disposables: vscode.Disposable[];
 
     private constructor(panel: vscode.WebviewPanel) {
@@ -77,7 +79,8 @@ export class Simulator {
     async simulateAsync(binaryJS: string) {
         this.binaryJS = binaryJS;
         this.panel.webview.html = "";
-        const simulatorHTML = await getSimHtmlAsync();
+        const simulatorHTML = await getSimLoaderHtmlAsync();
+        this.simHtml = await getSimHtmlAsync(activeWorkspace());
         if (this.simState == null) {
             this.simState = await extensionContext.workspaceState.get("simstate", {});
         }
@@ -99,7 +102,8 @@ export class Simulator {
             case "fetch-js":
                 this.postMessage({
                     ...message,
-                    text: this.binaryJS
+                    text: this.binaryJS,
+                    srcDoc: this.simHtml
                 });
                 break;
             case "bulkserial":
@@ -151,7 +155,7 @@ window.addEventListener("DOMContentLoaded", () => {
 `;
 
 
-async function getSimHtmlAsync() {
+async function getSimLoaderHtmlAsync() {
     const index = simloaderFiles["index.html"];
     const loaderJs = simloaderFiles["loader.js"];
     let customJs = simloaderFiles["custom.js"];