plugin reselection

Summary: When relaunching Flipper/refreshing it while developing, where was a case, where the App Client connected, before the device was registered in Flipper. In this case, we didn't select the previously selected plugin

Reviewed By: jknoxville

Differential Revision: D9359779

fbshipit-source-id: 9c6f8e6bf65a46dc84c9781242b23df0ed539810

src/reducers/connections.js

@@ -102,17 +102,27 @@ export default function reducer(
     case 'REGISTER_DEVICE': {
       const {payload} = action;
       const devices = state.devices.concat(payload);
-      let {selectedDevice} = state;
-      let selection = {};
+      let {selectedDevice, selectedPlugin} = state;
 
-      if (!selectedDevice) {
-        selectedDevice = payload;
-        selection = {
+      // select the default plugin
+      let selection = {
         selectedApp: null,
         selectedPlugin: DEFAULT_PLUGIN,
       };
+
+      if (!selectedDevice) {
+        selectedDevice = payload;
+        if (selectedPlugin) {
+          // We already had a plugin selected, but no device. This is happening
+          // when the Client connected before the Device.
+          selection = {};
+        }
       } else if (payload.title === state.userPreferredDevice) {
         selectedDevice = payload;
+      } else {
+        // We didn't select the newly connected device, so we don't want to
+        // change the plugin.
+        selection = {};
       }
 
       return {