fix(dev-mode): Don’t save to config.json, use flag instead

Turns out even the built, packaged version of the app can be restarted into dev mode by adding `—dev` to argv and using the new relaunch API.

src/browser/application-menu.coffee

@@ -13,8 +13,6 @@ class ApplicationMenu
     @setActiveTemplate(@getDefaultTemplate())
     global.application.autoUpdateManager.on 'state-changed', (state) =>
       @updateAutoupdateMenuItem(state)
-    global.application.config.observe 'devMode', (state) =>
-      @updateDevModeItem()
 
   # Public: Updates the entire menu with the given keybindings.
   #

src/browser/application.es6

@@ -319,17 +319,20 @@ export default class Application extends EventEmitter {
     });
 
     this.on('application:install-update', () => {
-      this.quitting = true
-      this.windowManager.cleanupBeforeAppQuit()
-      this.autoUpdateManager.install()
+      this.quitting = true;
+      this.windowManager.cleanupBeforeAppQuit();
+      this.autoUpdateManager.install();
     });
 
     this.on('application:toggle-dev', () => {
-      this.devMode = !this.devMode;
-      this.config.set('devMode', this.devMode ? true : undefined);
-      this.windowManager.destroyAllWindows();
-      this.windowManager.devMode = this.devMode;
-      this.openWindowsForTokenState();
+      let args = process.argv.slice(1);
+      if (args.includes('--dev')) {
+        args = args.filter(a => a !== '--dev');
+      } else {
+        args.push('--dev')
+      }
+      app.relaunch({args});
+      app.quit();
     });
 
     if (process.platform === 'darwin') {

src/browser/window-launcher.es6

@@ -36,12 +36,7 @@ export default class WindowLauncher {
   }
 
   newWindow(options) {
-    // Normally, you enter dev mode by passing the --dev command line flag.
-    // But for developers using the compiled app, it's easier to toggle dev
-    // mode from the menu and have it persist through relaunch.
-    const devOpt = this.config.get('devMode') ? {devMode: true} : {};
-
-    const opts = Object.assign({}, this.defaultWindowOpts, devOpt, options);
+    const opts = Object.assign({}, this.defaultWindowOpts, options);
 
     let win;
     if (this._mustUseColdWindow(opts)) {