refactor: make applicationMenu a property on app (#17361)

lib/browser/api/app.ts

@@ -19,9 +19,11 @@ Object.setPrototypeOf(App.prototype, EventEmitter.prototype)
 EventEmitter.call(app as any)
 
 Object.assign(app, {
+  // TODO(codebytere): remove in 7.0
   setApplicationMenu (menu: Electron.Menu | null) {
     return Menu.setApplicationMenu(menu)
   },
+  // TODO(codebytere): remove in 7.0
   getApplicationMenu () {
     return Menu.getApplicationMenu()
   },
@@ -38,6 +40,17 @@ Object.assign(app, {
 
 app.getFileIcon = deprecate.promisify(app.getFileIcon)
 
+// we define this here because it'd be overly complicated to
+// do in native land
+Object.defineProperty(app, 'applicationMenu', {
+  get () {
+    return Menu.getApplicationMenu()
+  },
+  set (menu: Electron.Menu | null) {
+    return Menu.setApplicationMenu(menu)
+  }
+})
+
 app.isPackaged = (() => {
   const execFile = path.basename(process.execPath).toLowerCase()
   if (process.platform === 'win32') {

lib/browser/api/top-level-window.js

@@ -12,7 +12,7 @@ TopLevelWindow.prototype._init = function () {
 
   // Simulate the application menu on platforms other than macOS.
   if (process.platform !== 'darwin') {
-    const menu = app.getApplicationMenu()
+    const menu = app.applicationMenu
     if (menu) this.setMenu(menu)
   }
 }