testing Angular async services with Jasmine

Question

I am trying to test a real http call with Jasmine (integration test), but when i call a method that uses $http.get, it times out and the server never gets called.

I know that I am supposed to inject the implementation of $http but not sure where that should happen.

searchSvc

app.service('searchSvc', ['$http', '$q', searchSvc]);
function searchSvc($http, $q) {
  return {
    search: function(text) {
      console.log('svc.search called with ', text); // this does get called 
      return $q.when($http.get('/search/' + text));
    }
  };
}

searchSpec

describe("searchTest", function() {
  var ctrl, svc, $http;

  beforeEach(function () {
      module('testApp');
    inject(function(_$controller_, searchSvc, _$http_){
      ctrl = _$controller_('searchCtrl');
      svc = searchSvc;
      $http = _$http_;
    })
  });

  it('test server search', function(done) {
      svc.search('re').then(function(result) {
        console.log('promise then'); // this never gets called, because server never gets called
        expect(result).not.toBeNull();
        expect(result.data).not.toBeNull();
        expect(result.data.length).toBeGreaterThan(0);

        done();
      });
  });

Answer 1

In case if you use promises you can find out how to deal with them here http://entwicklertagebuch.com/blog/2013/10/how-to-handle-angularjs-promises-in-jasmine-unit-tests/

Answer 2

This is sort of hypothetical, but if you include both ngMock & ngMockE2E modules as your app module's dependency (ngMock needs to come before ngMockE2E in the dependency list) you should be able to use $httpBackend service provided by ngMockE2E module to passThrough the search api call to actual backend in your test specs.

Try something like this and see whether it works:

describe("searchTest", function() {
  var ctrl, svc, $httpBackend;

  beforeEach(function () {
    module('testApp');
    inject(function(_$controller_, searchSvc, _$httpBackend_){
      $httpBackend = _$httpBackend_;
      ctrl = _$controller_('searchCtrl');
      svc = searchSvc;
    });
  });

  it('test server search', function(done) {
      $httpBackend.whenGET(/^\/search\//).passThrough();
      svc.search('re').then(function(result) {
        console.log('promise then'); // this never gets called, because server never gets called
        expect(result).not.toBeNull();
        expect(result.data).not.toBeNull();
        expect(result.data.length).toBeGreaterThan(0);

        done();
      });
  });
});

Answer 3

Here is a solution that I use to make real HTTP calls when I'm using ngMock for unit tests. I mainly use it for debugging, working through the test, getting JSON examples etc.

I wrote a more detailed post about the solution on my blog: How to Unit Test with real HTTP calls using ngMockE2E & passThrough.

The solution is as follows:

angular.mock.http = {};

angular.mock.http.init = function() {

  angular.module('ngMock', ['ng', 'ngMockE2E']).provider({
    $exceptionHandler: angular.mock.$ExceptionHandlerProvider,
    $log: angular.mock.$LogProvider,
    $interval: angular.mock.$IntervalProvider,
    $rootElement: angular.mock.$RootElementProvider
  }).config(['$provide', function($provide) {
    $provide.decorator('$timeout', angular.mock.$TimeoutDecorator);
    $provide.decorator('$$rAF', angular.mock.$RAFDecorator);
    $provide.decorator('$$asyncCallback', angular.mock.$AsyncCallbackDecorator);
    $provide.decorator('$rootScope', angular.mock.$RootScopeDecorator);
    $provide.decorator('$controller', angular.mock.$ControllerDecorator);
  }]);

};

angular.mock.http.reset = function() {

  angular.module('ngMock', ['ng']).provider({
    $browser: angular.mock.$BrowserProvider,
    $exceptionHandler: angular.mock.$ExceptionHandlerProvider,
    $log: angular.mock.$LogProvider,
    $interval: angular.mock.$IntervalProvider,
    $httpBackend: angular.mock.$HttpBackendProvider,
    $rootElement: angular.mock.$RootElementProvider
  }).config(['$provide', function($provide) {
    $provide.decorator('$timeout', angular.mock.$TimeoutDecorator);
    $provide.decorator('$$rAF', angular.mock.$RAFDecorator);
    $provide.decorator('$$asyncCallback', angular.mock.$AsyncCallbackDecorator);
    $provide.decorator('$rootScope', angular.mock.$RootScopeDecorator);
    $provide.decorator('$controller', angular.mock.$ControllerDecorator);
  }]);

};

Include this source file after ngMock, for example:

<script type="text/javascript" src="angular.js"></script>
<script type="text/javascript" src="angular-mocks.js"></script>
<!-- this would be the source code just provided -->
<script type="text/javascript" src="ngMockHttp.js"></script>

How to write the test?

  describe('http tests', function () {

    beforeEach(module('moviesApp'));

    var $controller;
    var $httpBackend;
    var $scope;

    describe('real http tests', function() {

      beforeEach(angular.mock.http.init);
      afterEach(angular.mock.http.reset);

      beforeEach(inject(function(_$controller_, _$httpBackend_) {
        $controller = _$controller_;
        $scope = {};
        $httpBackend = _$httpBackend_;

        // Note that this HTTP backend is ngMockE2E's, and will make a real HTTP request
        $httpBackend.whenGET('http://www.omdbapi.com/?s=terminator').passThrough();
      }));

      it('should load default movies (with real http request)', function (done) {
        var moviesController = $controller('MovieController', { $scope: $scope });

        setTimeout(function() {
          expect($scope.movies).not.toEqual([]);
          done();
        }, 1000);

      });

    });

  });

How it works?

It uses ngMockE2E's version of $httpBackEndProvider, which provides us with the passThrough function we see being used in the test. This does as the name suggests and lets a native HTTP call pass through.

We need to re-define the ngMock module without its fake version of the $BrowserProvider, since that is what prevents the real HTTP calls in unit tests that use ngMock.