How to trigger $onInit or $onChanges implictly in unit testing Angular component controller?

Question

I\'m using Angular 1.5.5 and Jasmine as test framework. Currently I have to do something like this so that the test passes:

function createController(bindings) {         


        

Answer 1

I don't know if this will help, but for testing components I do the following

beforeEach(module('templates'));

var element;        
var scope;

beforeEach(inject(function ($rootScope, $compile) {
    scope = $rootScope.$new();
    scope.draw = new ol.source.Vector({ wrapX: false });
    element = angular.element('<custom-element draw="draw"></custom-element>');
    element = $compile(element)(scope);
}));

var controller;
beforeEach(inject(function ($rootScope, $componentController) {
    scope = $rootScope.$new();
    scope.draw = new ol.source.Vector({ wrapX: false });
    controller = $componentController('customElement', {draw: new ol.source.Vector({ wrapX: false })}, { $scope: scope });
}));

and $onInit() and $onChanges() get triggered when they should be, by themselves

Answer 2

There is an issue in github regarding this: https://github.com/angular/angular.js/issues/14129

Basically it is working as intended, not calling $onInit or $onChanges automatically.

it makes no sense (or low sense) to execute $onInit, I explain it: $componentController is to instance controllers a kind of replacement for $controller, but instead of creating instances of controllers registered by the controllerProvider it creates instances of controllers registered through directives (the ones that satisfies a component definition). So, once you have the instance of the controller, you can call manually $onInit, and all the lifecycle of your controller, the idea is that you are testing a controller, not a directive (and its relationships).

Answer 3

You would require to take reference of controller from compiled version of element. As shown below:

describe('Component: Test Method', function () {

        beforeEach(inject(function (_$rootScope_) {
            scope = _$rootScope_.$new();
        }));


        it('should set value of selectedPackage to null after $onChanges event', inject(function ($compile) {
            // Trigger 1st $onChanges
            scope.selectedPackage = 'packageCode';

            var element = angular.element('<select-my-tv selected-package="selectedPackage"></select-my-tv>');
            element = $compile(element)(scope);
            scope.$digest();

            //Extract the Controller reference from compiled element
            var elementController = element.isolateScope().$ctrl;

            // Assert
            expect(elementController.selectedPackage).toBeNull();
        }));
    });
});