Wait 2s before checking for matching devices for connected clients

Summary:
Currently when a client connects, if there's no matching device we know of, it emits an error.

The problem is that there's a race between clients connecting and devices being detected, if the client connects first, then we'll emit this error, even though the device is displayed shortly afterwards.

Fixing this by waiting 2 seconds after a client connects, and then if it's still connected, checking for a matching device. This should be enough time to make this error more reliable.

Reviewed By: passy

Differential Revision: D14126315

fbshipit-source-id: c81b2c6d9a6e0639a656d1a4d7a8f999f715bfbf

src/dispatcher/server.js

@@ -21,6 +21,13 @@ export default (store: Store, logger: Logger) => {
       type: 'NEW_CLIENT',
       payload: client,
     });
+    // Wait 2 seconds, and then trigger another event so we can check it's displayed
+    setTimeout(() => {
+      store.dispatch({
+        type: 'NEW_CLIENT_SANITY_CHECK',
+        payload: client,
+      });
+    }, 2000);
   });
 
   server.addListener('removed-client', (id: string) => {

src/reducers/connections.js

@@ -70,6 +70,10 @@ export type Action =
       type: 'NEW_CLIENT',
       payload: Client,
     }
+  | {
+      type: 'NEW_CLIENT_SANITY_CHECK',
+      payload: Client,
+    }
   | {
       type: 'CLIENT_REMOVED',
       payload: string,
@@ -237,16 +241,6 @@ export default function reducer(
         selectedPlugin = userPreferredPlugin;
       }
 
-      const matchingDeviceForClient = state.devices.filter(
-        device => payload.query.device_id === device.serial,
-      );
-      if (matchingDeviceForClient.length === 0) {
-        console.error(
-          new RecurringError(`Client initialised for non-displayed device`),
-          payload.id,
-        );
-      }
-
       return {
         ...state,
         clients: state.clients.concat(payload),
@@ -260,6 +254,26 @@ export default function reducer(
         selectedPlugin,
       };
     }
+    case 'NEW_CLIENT_SANITY_CHECK': {
+      const {payload} = action;
+      // Check for clients initialised when there is no matching device
+      const clientIsStillConnected = state.clients.filter(
+        client => client.id == payload.query.device_id,
+      );
+      if (clientIsStillConnected) {
+        const matchingDeviceForClient = state.devices.filter(
+          device => payload.query.device_id === device.serial,
+        );
+        if (matchingDeviceForClient.length === 0) {
+          console.error(
+            new RecurringError(`Client initialised for non-displayed device`),
+            payload.id,
+          );
+        }
+      }
+
+      return state;
+    }
     case 'CLIENT_REMOVED': {
       const {payload} = action;