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ajax.js

Testing ajax calls

We have written a plugin called jasmine-ajax that allows ajax calls to be mocked out in tests. To use it, you need to download the mock-ajax.js file and add it to your jasmine helpers so it gets loaded before any specs that use it.

 
describe("mocking ajax", function() {

Basic Usage Across An Entire Suite

 
  describe("suite wide usage", function() {

When you want to mock out all ajax calls across an entire suite, use install() in a beforeEach.

 
    beforeEach(function() {
      jasmine.Ajax.install();
    });

Because jasmine-ajax stubs out the global XMLHttpRequest for the page, you’ll want to uninstall() in an afterEach so specs or setup that expect to make a real ajax request can.

 
    afterEach(function() {
      jasmine.Ajax.uninstall();
    });

    it("specifying response when you need it", function() {
      var doneFn = jasmine.createSpy("success");

Make your requests as normal. Jasmine-Ajax mocks out your request at the XMLHttpRequest object, so should be compatible with other libraries that do ajax requests.

 
      var xhr = new XMLHttpRequest();
      xhr.onreadystatechange = function(args) {
        if (this.readyState == this.DONE) {
          doneFn(this.responseText);
        }
      };

      xhr.open("GET", "/some/cool/url");
      xhr.send();

At this point the ajax request won’t have returned, so any assertions about intermediate states (like spinners) can be run here.

 
      expect(jasmine.Ajax.requests.mostRecent().url).toBe('/some/cool/url');
      expect(doneFn).not.toHaveBeenCalled();

Now we tell the request what it’s response should look like

 
      jasmine.Ajax.requests.mostRecent().respondWith({

HTTP response code

 
        "status": 200,

You can also specify the content type of the response

 
        "contentType": 'text/plain',

responseText to return, this should be a string.

 
        "responseText": 'awesome response'
      });

Now that we’ve told the request to respond, our callback gets called.

 
      expect(doneFn).toHaveBeenCalledWith('awesome response');
    });

You can also specify responses ahead of time and they will respond immediately when the request is made.

 
    it("allows responses to be setup ahead of time", function () {
      var doneFn = jasmine.createSpy("success");

Call stubRequest with the url you want to return immediately. Then andReturn receives the same type of argument as respondWith.

 
      jasmine.Ajax.stubRequest('/another/url').andReturn({
        "responseText": 'immediate response'
      });

Make your requests as normal

 
      var xhr = new XMLHttpRequest();
      xhr.onreadystatechange = function(args) {
        if (this.readyState == this.DONE) {
          doneFn(this.responseText);
        }
      };

      xhr.open("GET", "/another/url");
      xhr.send();

      expect(doneFn).toHaveBeenCalledWith('immediate response');
    });
  });

If you only want to use it in a single spec, you can use withMock. withMock takes a function that will be called after ajax has been mocked, and the mock will be uninstalled when the function completes.

 
  it("allows use in a single spec", function() {
    var doneFn = jasmine.createSpy('success');
    jasmine.Ajax.withMock(function() {
      var xhr = new XMLHttpRequest();
      xhr.onreadystatechange = function(args) {
        if (this.readyState == this.DONE) {
          doneFn(this.responseText);
        }
      };

      xhr.open("GET", "/some/cool/url");
      xhr.send();

      expect(doneFn).not.toHaveBeenCalled();

      jasmine.Ajax.requests.mostRecent().respondWith({
        "status": 200,
        "responseText": 'in spec response'
      });

      expect(doneFn).toHaveBeenCalledWith('in spec response');
    });
  });
});