mock $httpBackend in angular e2e tests

Question

Does anyone have an idea how to mock $httpBackend in angular e2e tests? The idea is stubbing XHR requests while running tests on travis-ci. I'm using karma to proxy assets and partials from my rails app running on travis. I want to do acceptance testing without real DB queries.

Here is part of my karma config file:

...
files = [
  MOCHA,
  MOCHA_ADAPTER,

  'spec/javascripts/support/angular-scenario.js',
  ANGULAR_SCENARIO_ADAPTER,

  'spec/javascripts/support/angular-mocks.js',
  'spec/javascripts/e2e/**/*_spec.*'
];
...

proxies = {
  '/app': 'http://localhost:3000/',
  '/assets': 'http://localhost:3000/assets/'
};
...

Here is part of my spec file:

beforeEach(inject(function($injector){
  browser().navigateTo('/app');
}));

it('should do smth', inject(function($rootScope, $injector){
  input('<model name>').enter('smth');
  //this is the point where I want to stub real http query
  pause();
}));

I have tried to receive $httpBackend service through $injector:

$injector.get('$httpBackend')

But this is not the one that is used inside iframe where my tests run.

The next try I made was using angular.scenario.dsl, here is code samle:

angular.scenario.dsl('mockHttpGet', function(){
  return function(path, fakeResponse){
    return this.addFutureAction("Mocking response", function($window, $document, done) {
      // I have access to window and document instances 
      // from iframe where my tests run here
      var $httpBackend =  $document.injector().get(['$httpBackend']);
      $httpBackend.expectGET(path).respond(fakeResponse)
      done(null);
    });
  };
});

Usage example:

it('should do smth', inject(function($rootScope, $injector){
  mockHttpGet('<path>', { /* fake data */ });
  input('search.name').enter('mow');
  pause();
}));

This leads to following error:

<$httpBackend listing>  has no method 'expectGET'

So, at this point I have no idea of next step. Have anyone tried doing something like this, is this type of stubbing really possible?

Answer 1

If you are really trying to mock out the backend in a E2E test (these tests are called Scenarios, while Specs are used for unit testing) then this is what I did in a project I was working on earlier.

The application I was testing was called studentsApp. It was an application to search for students by querying a REST api. I wanted to test the application without actually querying that api.

I created a E2E application called studentsAppDev that I inject studentsApp and ngMockE2E into. There I define what calls the mockBackend should expect and what data to return. The following is an example of my studentsAppDev file:

"use strict";

// This application is to mock out the backend. 
var studentsAppDev = angular.module('studentsAppDev', ['studentsApp', 'ngMockE2E']);
studentsAppDev.run(function ($httpBackend) {

    // Allow all calls not to the API to pass through normally
    $httpBackend.whenGET('students/index.html').passThrough();

    var baseApiUrl = 'http://localhost:19357/api/v1/';
    var axelStudent = {
        Education: [{...}],
        Person: {...}
    };
    var femaleStudent = {
        Education: [{...}],
        Person: {...}
    };
    $httpBackend.whenGET(baseApiUrl + 'students/?searchString=axe&')
        .respond([axelStudent, femaleStudent]);
    $httpBackend.whenGET(baseApiUrl + 'students/?searchString=axel&')    
        .respond([axelStudent, femaleStudent]);
    $httpBackend.whenGET(baseApiUrl + 'students/?searchString=axe&department=1&')
        .respond([axelStudent]);
    $httpBackend.whenGET(baseApiUrl + 'students/?searchString=axe&department=2&')
        .respond([femaleStudent]);
    $httpBackend.whenGET(baseApiUrl + 'students/?searchString=axe&department=3&')    
        .respond([]);

    ...

    $httpBackend.whenGET(baseApiUrl + 'departments/?teachingOnly=true')
        .respond([...]);
    $httpBackend.whenGET(baseApiUrl + 'majors?organization=RU').respond([...]);
});

Then, I have a first step in my Jenkins CI server to replace the studentsApp with studentsAppDev and add a reference to angular-mocks.js in the main index.html file.