Replacing Cache-Control header with nonce

Makes long polling work on IE10 and IE9

client-ts/Microsoft.AspNetCore.SignalR.Client.TS/Transports.ts

@@ -247,12 +247,12 @@ export class LongPollingTransport implements ITransport {
         }
 
         this.pollXhr = pollXhr;
-        this.pollXhr.open("GET", url, true);
+
+        this.pollXhr.open("GET", `${url}&_=${Date.now()}`, true);
         if (transferMode === TransferMode.Binary) {
             this.pollXhr.responseType = "arraybuffer";
         }
-        // IE caches xhr requests
+
-        this.pollXhr.setRequestHeader("Cache-Control", "no-cache");
         // TODO: consider making timeout configurable
         this.pollXhr.timeout = 120000;
         this.pollXhr.send();

client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/common.js

@@ -6,7 +6,10 @@
 var ECHOENDPOINT_URL = "http://" + document.location.host + "/echo";
 
 function getTransportTypes() {
-    var transportTypes = [signalR.TransportType.WebSockets];
+    var transportTypes = [];
+    if (typeof WebSocket !== "undefined") {
+        transportTypes.push(signalR.TransportType.WebSockets);
+    }
     if (typeof EventSource !== "undefined") {
         transportTypes.push(signalR.TransportType.ServerSentEvents);
     }
@@ -22,7 +25,12 @@ function eachTransport(action) {
 }
 
 function eachTransportAndProtocol(action) {
-    var protocols = [new signalR.JsonHubProtocol(), new signalRMsgPack.MessagePackHubProtocol()];
+    var protocols = [new signalR.JsonHubProtocol()];
+    // IE9 does not support XmlHttpRequest advanced features so disable for now
+    // This can be enabled if we fix: https://github.com/aspnet/SignalR/issues/742
+    if (typeof new XMLHttpRequest().responseType === "string") {
+        protocols.push(new signalRMsgPack.MessagePackHubProtocol());
+    }
     getTransportTypes().forEach(function (t) {
         return protocols.forEach(function (p) {
             return action(t, p);

client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/connectionTests.js

@@ -4,6 +4,7 @@
 "use strict";
 
 describe('connection', function () {
+    if (typeof WebSocket !== 'undefined') {
         it("can connect to the server without specifying transport explicitly", function (done) {
             var message = "Hello World!";
             var connection = new signalR.HttpConnection(ECHOENDPOINT_URL);
@@ -28,6 +29,7 @@ describe('connection', function () {
                 done();
             });
         });
+    }
 
     eachTransport(function (transportType) {
         it("over " + signalR.TransportType[transportType] + " can send and receive messages", function (done) {

client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/webSocketTests.js

@@ -3,6 +3,7 @@
 
 'use strict';
 
+if (typeof WebSocket !== 'undefined') {
     describe('WebSockets', function () {
         it('can be used to connect to SignalR', function (done) {
             var message = "message";
@@ -33,3 +34,4 @@ describe('WebSockets', function () {
             };
         });
     });
+}