Emulate Apex Calls

mocha-aura can mock success and failure apex calls. Your callback will be invoked synchronously during $A.enqueueAction call.

it('should call checkSelection', function() {

  //Fake result from APEX code
  const attendeeObj = {
    id: 123,
    name: 'test'
  }
  // Create an instance with success response and payload
  const result = apexSuccessResult(attendeeObj);
  
  // Create Apex call object
  const declineRSVP = apexCallFactory(result);

  // Specify Apex call object among other variables during component creation
  const component = componentFactory({
    attendeeObj: {id: 456},
    declineRSVP
  });

  const cb = sinon.spy();

  helper.declineAttendeeRSVP(component, cb);
  expect(declineRSVP.getParams()).to.eql({attendeeId: 456});
  expect(helper.checkSelection).to.have.been.calledWith(component);
  expect(cb).to.have.been.calledWith(component);
  // Check that attendeeObject has data from Apex call  
  expect(component.get('v.attendeeObj')).to.equal(attendeeObj);

});