TypeError: Cannot read property 'then' of undefined angularjs-grunt test

angularjs, karma-runner, q, unit-testing

Solution

If you only need to find out whether `getFilterData` is called or not, try returning a fake promise by faking the function:

With jasmine 1.3, we could use `andCallFake`:

it('should call getFilterData() in bindFilters()', function () {
    spyOn(scope, 'getFilterData').andCallFake(function(){//replace with a fake function
        var deferred = $q.defer(); //assume that you already inject $q service in beforeEach and save it as a variable.
        return deferred.promise; //returns a fake promise
    });
    scope.bindFilters();
    expect(scope.getFilterData).toHaveBeenCalled();
  });

With jasmine 2.0, we could use `and.callFake` instead.

Another solution is to use `andReturnValue` and `$q.when()`:

it('should call getFilterData() in bindFilters()', function () {
        spyOn(scope, 'getFilterData').andReturnValue($q.when());
        scope.bindFilters();
        expect(scope.getFilterData).toHaveBeenCalled();
      });

With jasmine 2.0, we could use `and.returnValue` instead.

Problem

I'm using $q service to make an async calls. I can't resolve 'then' and 'defer' in unit tests using karma. The below is my controller code. ``` scope.filterUrls = [{url:'page1'}, {url: 'page2'}, {url:'page-error'}]; scope.bindFilters = function () { angular.forEach(scope.filterUrls, function (data) { scope.getFilterData(data.url, '').then(function (result) { if (data.url === 'page1') { scope.moduleData.index = result.data; } else if (data.url === 'page2') { scope.moduleData.page2 = result.data; } }); }); } scope.getFilterData = function (filterUrls, params) { // $q service object var deferred = q.defer(); // regular ajax request http({ method: 'GET', url: app.api.root + filterUrls, params: params }) .success(function (result) { // promise resolve deferred.resolve(result); }) .error(function (result) { // called asynchronously if an error occurs // or server returns response with an error status. deferred.reject('Erreur request : ' + result); }); return deferred.promise; }; ``` test spec: ``` it('should call getFilterData() in bindFilters()', function () { spyOn(scope, 'getFilterData'); scope.bindFilters(); expect(scope.getFilterData).toHaveBeenCalled(); }); ``` I'm getting an error called "TypeError: Cannot read property 'then' of undefined". How can I write an unit test for those two methods using karma. Update: 1.how do we can test the success and error of scope.getFilterData() 2 .then function in scope.bindFilters() function. Please help..

Original source