Wrap XMLHttp.prototype.send instead of open (fixes #453)

Author: benvinegar

src/raven.js

@@ -615,10 +615,10 @@ Raven.prototype = {
             }
         });
 
-        var origOpen;
+        var origSend;
         if ('XMLHttpRequest' in window) {
-            origOpen = XMLHttpRequest.prototype.open;
-            fill(XMLHttpRequest.prototype, 'open', function(origOpen) {
+            origSend = XMLHttpRequest.prototype.send;
+            fill(XMLHttpRequest.prototype, 'send', function(origOpen) {
                 return function (data) { // preserve arity
                     var xhr = this;
                     'onreadystatechange onload onerror onprogress'.replace(/\w+/g, function (prop) {
@@ -628,7 +628,7 @@ Raven.prototype = {
                             }, true /* noUndo */); // don't track filled methods on XHR instances
                         }
                     });
-                    origOpen.apply(this, arguments);
+                    origSend.apply(this, arguments);
                 };
             });
         }

test/integration/test.js

@@ -244,12 +244,20 @@ describe('integration', function () {
 
             iframeExecute(iframe, done,
               function () {
-                  setTimeout(done);
                   var xhr = new XMLHttpRequest();
+
+                  // intentionally assign event handlers *after* XMLHttpRequest.prototype.open,
+                  // since this is what jQuery does
+                  // https://github.com/jquery/jquery/blob/master/src/ajax/xhr.js#L37
+
+                  xhr.open('GET', 'example.json')
                   xhr.onreadystatechange = function () {
+                      setTimeout(done);
+                      // replace onreadystatechange with no-op so exception doesn't
+                      // fire more than once as XHR changes loading state
+                      xhr.onreadystatechange = function () {};
                       foo();
                   };
-                  xhr.open('GET', 'example.json');
                   xhr.send();
               },
               function () {