Separate Client in server and client part

Summary: This diff separates the concept of a Client as now on the UI, from the concept of a Client as known on the server, and makes all interactions with client and vice versa async.

Reviewed By: timur-valiev

Differential Revision: D31235682

fbshipit-source-id: 99089e9b390b4c5359f97f6f2b15bf4b182b6cb9

desktop/app/src/PluginContainer.tsx

@@ -49,6 +49,7 @@ import {produce} from 'immer';
 import {reportUsage} from './utils/metrics';
 import {PluginInfo} from './chrome/fb-stubs/PluginInfo';
 import {getActiveClient, getActivePlugin} from './selectors/connections';
+import {isTest} from './utils/isProduction';
 
 const {Text, Link} = Typography;
 
@@ -250,7 +251,7 @@ class PluginContainer extends PureComponent<Props, State> {
   render() {
     const {activePlugin, pluginKey, target, pendingMessages} = this.props;
     if (!activePlugin || !target || !pluginKey) {
-      return null;
+      return this.renderNoPluginActive();
     }
     if (activePlugin.status !== 'enabled') {
       return this.renderPluginInfo();
@@ -294,6 +295,9 @@ class PluginContainer extends PureComponent<Props, State> {
   }
 
   renderNoPluginActive() {
+    if (isTest()) {
+      return <>No plugin selected</>; // to keep 'nothing' clearly recognisable in unit tests
+    }
     return (
       <View grow>
         <Waiting>