Jasmine test the javascript function for url

Here is my code:

var getCode = function(code) {
if (code = (new RegExp('[?&]' + encodeURIComponent(code) + '=([^&]*)'))
        .exec(location.search))
    return decodeURIComponent(code[1]);
};

$(document).ready(function() {
var code = getCode("code");
//some other function

and here is my test code:

 it("check the code value of url", function() {
    window.location.search = "http://ift.tt/20aW4KF";
    var code = getCode("code");
    expect(code).toEqual("testParam");
});

Whenever I try to run this as jasmine test it shows runtimeexception. Is there anyway I can set the location url and check it?

Thank you very much for your help