jasmine.js expect() does not work inside an asynchronous callback

Question

I'm getting acquainted with Jasmine (http://pivotal.github.com/jasmine/) and found something rather baffling:

it("should be able to send a Ghost Request", function() {
  var api = fm.api_wrapper;

  api.sendGhostRequest(function(response) {
    console.dir('server says: ', response);
  });

  expect(true).toEqual(false);
});

Fails as expected.

However, moving the expect call inside the callback:

it("should be able to send a Ghost Request", function() {
  var api = fm.api_wrapper;

  api.sendGhostRequest(function(response) {
    console.dir('server says: ', response);
    expect(true).toEqual(false);
  });
});

Somehow passes :O

After some debugging: api.sendGhostRequest() does an asynchronous ajax request, and jasmine rushes past before the request has completed.

Hence the question:

How do I get jasmine to wait for ajax execution before ascertaining the test result?

Answer 1

Edit for Jasmine 2

Asynchronous tests have become much simpler in Jasmine 2. Any test that needs to handle asynchronous code can be written with a callback which will indicate the completion of the test. See the Jasmine 2 docs under the header Asynchronous Support

it('should be able to send a ghost request', (done) => {
    api.sendGhostRequest((response) => {
        console.log(`Server says ${response}`);
        expect(true).toEqual(false);
        done();
    });
});

Jasmine 1

Have a look at waitsFor() and runs() on the Jasmine site under the header Asynchronous Support.

Use of runs and waitsfor should force Jasmine to wait for the ajax call to finish or for some timeout.

The code would look like:

it("should be able to send a Ghost Request", function() {
    runs(function() {
        api.sendGhostRequest(function(response) {
            console.dir('server says: ', response);
            flag = true;
        });
    }, 500);

    waitsFor(function() {
        return flag;
    }, "Flag should be set", 750);

    runs(function() {
        expect(true).toEqual(false);
    });
}

In which case the expect would fail.