Reference Error in Jasmine tests: Can't find variable

I have a simple controller in my angular app, and the jasmine test spec for the same returns a Reference Error. My Controller code:

'use strict';
angular.module('taskListAppApp')
  .controller('MainCtrl', function ($scope) {
    $scope.todoList = [{
        todoText: 'In case of Fire',
        done: false
    }, {
        todoText: 'git commit',
        done: false
    }, {
        todoText: 'git push',
        done: false
    }, {
        todoText: 'exit the building!',
        done: false
    }];


    $scope.getTotalTodos = function () {
        return $scope.todoList.length;
    };


    $scope.todoAdd = function () {
        // Checking for null or empty string
        if (null !== $scope.taskDesc && "" !== $scope.taskDesc) {
            $scope.todoList.push({
                todoText: $scope.taskDesc,
                done: false
            });
        }
    };

    // Function to remove the list items
    $scope.remove = function () {
        var oldList = $scope.todoList;
        $scope.todoList = [];
        angular.forEach(oldList, function (x) {
            if (!x.done) {
                $scope.todoList.push(x);
            }
        });
    };
});

And my test spec:

    "use strict"

    describe('Controller: MainCtrl', function () {      //describe your object type
        // beforeEach(module('taskListNgApp2App')); //load module
        beforeEach(angular.mock.module('taskListAppApp'));
        describe('MainCtrl', function () { //describe your app name

            var todoCtrl2;
            beforeEach(inject(function ($controller, $rootScope) {
                var scope = $rootScope.$new();
                todoCtrl2 = $controller('MainCtrl', {
                    //What does this line do?
                    $scope: scope
                });
            }));

            it('should have todoCtrl defined', function () {
                expect(todoCtrl2).toBeDefined();
            });

        it('trial test for toEqual', function(){
          var a = 4;
          expect(a).toEqual(4);
        });
//THESE 2 FAIL
        it('should have todoList defined', function() {
            expect(scope.todoList).toBeDefined();
        });

        it('should have add method defined', function(){
            expect(todoCtrl2.todoAdd()).toBeDefined();
        });

    });
});

The error I get is:

PhantomJS 2.1.1 (Linux 0.0.0) Controller: MainCtrl MainCtrl should have add method defined FAILED
    TypeError: undefined is not a function (evaluating 'todoCtrl2.todoAdd()') in test/spec/controllers/main.spec.js (line 58)
    test/spec/controllers/main.spec.js:58:28
    loaded@http://localhost:8080/context.js:151:17
PhantomJS 2.1.1 (Linux 0.0.0): Executed 4 of 4 (2 FAILED) (0.05 secs / 0.02 secs)

I tried other ways to call the objects/functions, but the last 2 tests are failing every time with the same error viz. ReferenceError

Where am I going in calling the objects?