From 5e042f603a1485fc54a4f3c4819b69e6a003e26c Mon Sep 17 00:00:00 2001
From: Keith Cirkel <keithamus@users.noreply.github.com>
Date: Thu, 4 Oct 2018 10:23:21 -0700
Subject: [PATCH] fix: be defensive around use of window.WebSocket

---
 robust-websocket.js | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/robust-websocket.js b/robust-websocket.js
index 8d3bcda..e6969ee 100644
--- a/robust-websocket.js
+++ b/robust-websocket.js
@@ -11,6 +11,8 @@
   }
 })(function(global, navigator) {
 
+  var WebSocket = global.WebSocket
+
   var RobustWebSocket = function(url, protocols, userOptions) {
     var realWs = { close: function() {} },
         connectTimeout,
@@ -75,6 +77,12 @@
     }
 
     self.send = function() {
+      if (realWs.readyState !== self.OPEN) {
+        throw Object.assign(
+          new Error('An attempt was made to use a WebSocket that is not usable'),
+          { name: 'InvalidStateError' }
+        )
+      }
       return realWs.send.apply(realWs, arguments)
     }
 
@@ -93,7 +101,7 @@
     }
 
     self.open = function() {
-      if (realWs.readyState !== WebSocket.OPEN && realWs.readyState !== WebSocket.CONNECTING) {
+      if (realWs.readyState !== self.OPEN && realWs.readyState !== self.CONNECTING) {
         clearPendingReconnectIfNeeded()
         reconnectWhenOnlineAgain = false
         explicitlyClosed = false
@@ -239,5 +247,16 @@
     }
   }
 
+  ['CONNECTING' , 'OPEN', 'CLOSING', 'CLOSED'].forEach(function (name) {
+    const descriptor = {
+      writable: false,
+      enumerable: true,
+      configurable: false,
+      value: WebSocket[name],
+    }
+    Object.defineProperty(RobustWebSocket, name, descriptor)
+    Object.defineProperty(RobustWebSocket.prototype, name, descriptor)
+  })
+
   return RobustWebSocket
 }, typeof window != 'undefined' ? window : (typeof global != 'undefined' ? global : this));