Capture Request Payload in Javascript

Question

The web appliation I am testing is making http calls out. I'm trying to set up a Qunit test to validate those calls. I need to be able to validate the data that is in the Request Payload of HTTP POST calls. I can already capture the call iteself but I don't have access to the Request Payload of that call.

Here's what I have so far:

XMLHttpRequest.prototype._originalOpen = XMLHttpRequest.prototype.open;
XMLHttpRequest.prototype.open = function(method, url, async, user, password) {
    if(url.match(/get/)) {
        QUnit.asyncTest("Validate URL", function( assert ) {
            assert.equal( url.match(my_regex)[0] , expected_url, "Matches");
            // assert.equal( /*Validate Request Payload*/);
            start();
        });
    }
    this._originalOpen(method, url, async, user, password);
}

Is there any way to capture the request payload of the call in Javascript?

Answer 1

You need to clone the send() method just like you did open, then inspect the arguments:

var clone = window.XMLHttpRequest.prototype.send;
window.XMLHttpRequest.prototype.send = function() {
  // console.log(arguments);
  // Continue the send
  clone.apply(this, arguments);
};