Yarn workspaces

Summary:
1) moved "sonar/desktop/src" to "sonar/desktop/app/src", so "app" is now a separate package containing the core Flipper app code
2) Configured yarn workspaces with the root in "sonar/desktop": app, static, pkg, doctor, headless-tests. Plugins are not included for now, I plan to do this later.

Reviewed By: jknoxville

Differential Revision: D20535782

fbshipit-source-id: 600b2301960f37c7d72166e0d04eba462bec9fc1

desktop/app/src/utils/js-client/webviewImpl.js

@@ -0,0 +1,63 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import {FlipperClient, FlipperBridge} from './api';
+
+import type {FlipperPluginID, FlipperMethodID} from './api';
+
+class FlipperWebviewBridgeImpl extends FlipperBridge {
+  _subscriptions: Map<string, (any) => void> = new Map();
+
+  registerPlugins = (plugins: Array<FlipperPluginID>) => {
+    window.FlipperWebviewBridge &&
+      window.FlipperWebviewBridge.registerPlugins(plugins);
+  };
+
+  start = (appName: string) => {
+    window.FlipperWebviewBridge && window.FlipperWebviewBridge.start(appName);
+  };
+
+  stop = () => {
+    window.FlipperWebviewBridge && window.FlipperWebviewBridge.stop();
+  };
+
+  sendData = (plugin: FlipperPluginID, method: FlipperMethodID, data: any) => {
+    window.FlipperWebviewBridge &&
+      window.FlipperWebviewBridge.sendFlipperObject(
+        plugin,
+        method,
+        JSON.stringify(data),
+      );
+  };
+
+  subscribe = (
+    plugin: FlipperPluginID,
+    method: FlipperMethodID,
+    handler: any => void,
+  ) => {
+    this._subscriptions.set(plugin + method, handler);
+  };
+
+  isAvailable = () => {
+    return window.FlipperWebviewBridge != null;
+  };
+
+  receive(plugin: FlipperPluginID, method: FlipperMethodID, data: string) {
+    const handler = this._subscriptions.get(plugin + method);
+    handler && handler(JSON.parse(data));
+  }
+}
+
+export function newWebviewClient(): FlipperClient {
+  const bridge = new FlipperWebviewBridgeImpl();
+  window.flipper = {
+    FlipperWebviewMessageReceiver: bridge,
+  };
+  return new FlipperClient(bridge);
+}