Proper way to jQuery.ajax mocking

jQuery.ajax method returns Deferred object, so it's ease to write parametrized version of ajax mock (example in Jasmine):

// Synchronous jQuery.ajax mock
spyOn(,ドル 'ajax').and.callFake(function(url) {
 var ajaxMock = $.Deferred();

 switch (url) {
 case undefined:
 ajaxMock.resolve({
 'error': 'Please use POST request'
 });
 break;
 case 'valid_url':
 ajaxMock.resolve('some data');
 break;
 default: // invalid url
 ajaxMock.reject();
 }

 return ajaxMock.promise();
});

And that is the equivalent of ajax synchronous request. But it's better not to use that type of requests, because they can lock a browser (remember that A in AJAX means asynchronous?).

To get asynchronous request you need to add timeout:

// Asynchronous jQuery.ajax mock
spyOn(,ドル 'ajax').and.callFake(function(url) {
 var ajaxMock = $.Deferred();

 setTimeout(function() {
 switch (url) {
 case undefined:
 ajaxMock.resolve({
 'error': 'Please use POST request'
 });
 break;
 case 'valid_url':
 ajaxMock.resolve('some data');
 break;
 default: // invalid url
 ajaxMock.reject();
 }
 }, 5);

 return ajaxMock.promise();
});

That's all. Enjoy your new mock.