From 0c949268e8c696e90f350b2e0eb64fca7ff8c20a Mon Sep 17 00:00:00 2001
From: Marc Glasser <marc@expensify.com>
Date: Fri, 11 Sep 2020 11:44:25 -0700
Subject: [PATCH] add reconnect logic for Pusher

---
 src/lib/API.js           | 14 ++++++++++++++
 src/lib/Pusher/pusher.js |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/src/lib/API.js b/src/lib/API.js
index e9bb87454281..01d92b384798 100644
--- a/src/lib/API.js
+++ b/src/lib/API.js
@@ -262,6 +262,16 @@ function processNetworkRequestQueue() {
 // Process our write queue very often
 setInterval(processNetworkRequestQueue, 1000);
 
+/**
+ * Pusher.reconnect() calls disconnect and connect on the
+ * Pusher socket. In some cases, the authorizer might fail
+ * or an error will be returned due to an out of date authToken.
+ * Reconnect will preserve our existing subscriptions and retry
+ * connecting until it succeeds. We're throttling this call so
+ * that we retry as few times as possible.
+ */
+const reconnectToPusher = _.throttle(Pusher.reconnect, 1000);
+
 /**
  * When authTokens expire they will automatically be refreshed.
  * The authorizer helps make sure that we are always passing the
@@ -284,6 +294,7 @@ Pusher.registerCustomAuthorizer((channel, {authEndpoint}) => ({
             .then(authResponse => authResponse.json())
             .then(data => callback(null, data))
             .catch((err) => {
+                reconnectToPusher();
                 console.debug('[Network] Failed to authorize Pusher');
                 callback(new Error(`Error calling auth endpoint: ${err}`));
             });
@@ -311,6 +322,9 @@ Pusher.registerSocketEventCallback((eventName, data) => {
                 isCurrentlyOffline = true;
             }
             break;
+        case 'error':
+            reconnectToPusher();
+            break;
         default:
             break;
     }
diff --git a/src/lib/Pusher/pusher.js b/src/lib/Pusher/pusher.js
index 97278d0f0c98..7c9f209fb148 100644
--- a/src/lib/Pusher/pusher.js
+++ b/src/lib/Pusher/pusher.js
@@ -354,6 +354,14 @@ function disconnect() {
     socket = null;
 }
 
+/**
+ * Disconnect and Re-Connect Pusher
+ */
+function reconnect() {
+    socket.disconnect();
+    socket.connect();
+}
+
 if (window) {
     /**
      * Pusher socket for debugging purposes
@@ -376,4 +384,5 @@ export {
     registerSocketEventCallback,
     registerCustomAuthorizer,
     disconnect,
+    reconnect,
 };