Test AngularJS, which returns a promise without calling $ rootScope. $ Apply ()?

Question

I have an AngularJS service that returns a promise.

Although the code works fine, the test gives me some difficulties, since the "then" promise method is never called in my unit test.

The general answer is a call $rootScope.$apply(), as mentioned in the post “ Continuous AngularJS Callback in JasmineJS Test ”. However, if I do, my test tries to load load templates/home.html, which is not expected:

PhantomJS 1.9.7 (Linux) Controller: ScanCtrl should invoke the barcode scanner when it is available FAILED
    Error: Unexpected request: GET templates/home.html
    No more request expected

If I don’t include it $rootScope.$apply(), the then method of this promise is never called, and I get an error that my spy is not being called as expected:

PhantomJS 1.9.7 (Linux) Controller: ScanCtrl should invoke the barcode scanner when it is available FAILED
    Expected spy go to have been called with [ 'enterQuantity', { barcodeId : '888888888888' } ] but it was never called.

, : , ? $rootScope.$apply()? , templates/home.html, $rootScope.$apply()?

.factory('BarcodeScannerService', ['$q', function ($q) {
    return {
        scanBarcode: function () {

            var deferred = $q.defer();

            plugins.barcodeScanner.scan(
                function (result) {
                    console.log("We got a barcode\n" +
                        "Result: " + result.text + "\n" +
                        "Format: " + result.format + "\n" +
                        "Cancelled: " + result.cancelled);
                    deferred.resolve({"error": false, "barcode": result.text});

                },
                function (error) {
                    deferred.resolve({"error": true});
                });

            return deferred.promise;

        }            
    };
}]
)

Unit Test

it('should invoke the barcode scanner when it is available', function () {

    inject(function ($controller, $rootScope, $q) {
        scope = $rootScope.$new();
        $rootScopeHolder = $rootScope;
        var deferred = $q.defer();

        barcodeScannerServiceMock.scanBarcode = jasmine.createSpy('scanBarcode').andReturn(deferred.promise);
        deferred.resolve({"error": false, "barcode": fakeBarcode2});

        barcodeScannerServiceMock.isAvailable = jasmine.createSpy('isAvailable').andReturn(true);

        //$scope, $timeout, Items, $state, SubmitCartService, $window
        ScanCtrl = $controller('ScanCtrl', {
            $scope: scope,
            $window: windowMock,
            Items: itemMock,
            BarcodeScannerService: barcodeScannerServiceMock,
            $state: stateMock
        });

    });

    expect(barcodeScannerServiceMock.isAvailable).toHaveBeenCalled();
    expect(barcodeScannerServiceMock.scanBarcode).toHaveBeenCalled();
    //$rootScopeHolder.$apply();
    expect(stateMock.go).toHaveBeenCalledWith('enterQuantity', { barcodeId: fakeBarcode2 });

});

    .controller('ScanCtrl', function ($scope, $timeout, $ionicModal, $state, BarcodeScannerService, $window) {

        $scope.handleBarcodeScanError = function () {
            var r = $window.confirm("Scanning failed.  Try again?");
            if (r === true) {
                $state.go('scan');
            }
            else {
                $state.go('home');
            }
        };

        console.log("Scanner Avaialble?" + BarcodeScannerService.isAvailable());
        if (BarcodeScannerService.isAvailable() === true) {

            var barcodeResult = {};

            BarcodeScannerService.scanBarcode()
                .then(function(result){
                    barcodeResult = result;

                    if (barcodeResult.error === false) {
                        $state.go('enterQuantity', {barcodeId: barcodeResult.barcode});
                    }

                    else {
                        $scope.handleBarcodeScanError();
                    }

                }, function(error){
                    $scope.handleBarcodeScanError();
                });

        }
        //else, if barcode scanner is not available ask them to key it in
        else {
            var tempBarcode = $window.prompt('Enter barcode:');
            $state.go('enterQuantity', {barcodeId: tempBarcode});
        }


    }
)

: https://github.com/derekdata/barcode-cart-builder/

: www/js/app.js : www/js/services/services.js : www_test/spec/controllers/ScanCtrlTest.js

, .

Answer 1

, . $rootScope. $Digest(), $rootScope. $Apply(); $digest , promises , . , $digest() , . $Digest() .

Answer 2

$rootScope.$digest $rootScope.$apply, Q (https://github.com/kriskowal/q) , :

beforeEach(function () {
    module('Module', function ($provide) {
        $provide.value('$q', Q); 
    });
});

promises / $digest.