How do unit test with angular-translate

问题:

I have uses angular translate from here (http://pascalprecht.github.io/angular-translate/) and it's just work fine, but it break my controller's unit test whith Error:

Unexpected request: GET scripts/i18n/locale-en.json

I don't understant why?

I use yeoman and test with karma.

app.js:

'use strict';

(function() {

  angular.module('wbApp', ['authService', 'authUserService', 'checkUserDirective', 'ui.bootstrap', 'pascalprecht.translate'])
    .config(function($routeProvider) {
      $routeProvider
        .when('/', {
          templateUrl: 'views/login.html',
          controller: 'LoginCtrl',
          access: {
            isFree: true
          }
        })
        .when('/main', {
          templateUrl: 'views/main.html',
          controller: 'MainCtrl',
          access: {
            isFree: false
          }
        })
        .otherwise({
          redirectTo: '/'
        });
    });

})();

configTranslate.js:

'use strict';

(function() {

  angular.module('wbApp')
    .config(['$translateProvider',
      function($translateProvider) {

        $translateProvider.useStaticFilesLoader({
            prefix: 'scripts/i18n/locale-',
            suffix: '.json'
        });

        $translateProvider.preferredLanguage('en');

      }]);

})();

karma.conf.js:

files = [

  ...

  'app/bower_components/angular-translate/angular-translate.js',
  'app/bower_components/angular-translate-loader-static-files/angular-translate-loader-static-files.js',

  ...

];

controller test:

'use strict';

describe('Controller: LoginCtrl', function() {

  // load the controller's module
  beforeEach(module('wbApp'));

  var LoginCtrl, scope, location, httpMock, authUser;

  // Initialize the controller and a mock scope
  beforeEach(inject(function($controller, $rootScope, $location, $httpBackend, AuthUser) {
    authUser = AuthUser;
    location = $location;
    httpMock = $httpBackend;
    scope = $rootScope.$new();

    LoginCtrl = $controller('LoginCtrl', {
      $scope: scope
    });


    httpMock.when('GET', 'scripts/i18n/locale-en.json').passThrough();

  }));

  it(...);

  ...

});

if i add this in test controller, product same error:

httpMock.when('GET', 'scripts/i18n/locale-en.json').respond(200);
httpMock.flush();

or

httpMock.when('GET', 'scripts/i18n/locale-en.json').passThrough();
httpMock.flush();

i find this post How do I test controllers with Angular Translate initialized in App Config? but not helped me :/

I extensively use $httpBackend in my tests and it works fine, but in this case it is ineffective. If I comment the line:

$translateProvider.preferredLanguage('en');

obviously an error, if I add on the runtime (in my controllers)

$translate.uses(local);

I end up with the same error?

So I turn to the translation configuration (configTranslate.js) or at runtime is the same result:

Unexpected request: GET scripts/i18n/locale-en.json

Here is the syntax that I tested, either in a "beforeEach(inject(function(...});"

or in a test "it('...', function() {...});"

httpMock.expectGET('scripts/i18n/locale-en.json');
httpMock.when('GET', 'scripts/i18n/locale-en.json').passThrough();
httpMock.when('GET', 'scripts/i18n/locale-en.json').respond(data);

with at end

httpMock.flush();

I also tried a $ apply

httpMock.expectGET('scripts/i18n/locale-fr.json');
scope.$apply(function(){
  $translate.uses('fr');
});
httpMock.flush();

nothing happens, Still this error is driving me crazy ..

If you have any suggestion

回答1:

it's a known issue, please follow the documentation here: unit testing angular

The solution

Unfortunately, this issue is caused by the design of angular-translate. To get around these errors, all we can do is to overwrite our module configuration in our test suite, that it doesn't use asynchronous loader at all. When there's no asynchronous loader, there's no XHR and therefore no error.

So how do we overwrite our module configuration at runtime for our test suite? When instantiating an angular module, we can always apply a inline function which is executed as configuration function. This configuration function can be used to overwrite the modules configuration since we have access to all providers.

Using the $provide provider, we can build a custom loader factory, which should then be used instead of the static files loader.

beforeEach(module('myApp', function ($provide, $translateProvider) {

  $provide.factory('customLoader', function () {
    // loader logic goes here
  });

  $translateProvider.useLoader('customLoader');

}));

Please read more in the above link provided.

回答2:

We took the approach of ignoring the translation loader in unit tests, rather than being forced to modify each of the spec files.

One way to do it could be by separating the loader configuration to a separate file and then exclude it in karma.

So for example you can create a file app-i18n-loader.js (all other module configurations takes place in a different file):

    angular
    .module('myApp')
    .config(loaderConfig);

loaderConfig.$inject = ['$translateProvider', '$translatePartialLoaderProvider'];

function loaderConfig($translateProvider, $translatePartialLoaderProvider) {

    $translateProvider.useLoader('$translatePartialLoader', {
        urlTemplate: 'assets/i18n/{part}/{lang}.json'
    });

    $translatePartialLoaderProvider.addPart('myApp');
}

And in your karma.conf.js exclude the file:

        files: [
        'bower_components/angular/angular.js',
        'bower_components/angular-mocks/angular-mocks.js',
        //...
        'bower_components/angular-translate/angular-translate.js',
        'bower_components/angular-translate-loader-partial/angular-translate-loader-partial.js',
        'app/**/*.mdl.js',
        'app/**/*.js'
    ],

    exclude: [
        'app/app-i18n-loader.js'
    ],

(Note: Answer edited to a solution that does not require grunt/gulp).

回答3:

I wanted a solution,

1. which was not too hacky
2. which didn't require me to change my actual application code,
3. which wouldn't interfere with the ability to load additional modules
4. and most importantly which wouldn't require me to change every single test.

This is what I ended up with:

// you need to load the 3rd party module first
beforeEach(module('pascalprecht.translate'));
// overwrite useStaticFilesLoader to get rid of request to translation file
beforeEach(module(function ($translateProvider) {
    $translateProvider.useStaticFilesLoader = function () {
    };
}));

Assuming you don't need the actual translations for your unit tests, this works great. Just put the beforeEach on a global level, preferably in it's own file inside the test folder. It will be executed before every other test then.

回答4:

Try putting to test method:

it('should ...', function() {
    httpMock.when('GET', 'scripts/i18n/locale-en.json').respond({});
    httpMock.expectGET('scripts/i18n/locale-en.json');
    scope.resetForm(); // Action which fires a http request
    httpMock.flush(); // Flush must be called after the http request
}

See examples from Angular docs

回答5:

Please have a look at https://github.com/PascalPrecht/angular-translate/blob/master/test/unit/service/loader-static-files.spec.js as a reference.

In general, I would recommend using a standard translation loader for unit tests (without the hassle of http loadings) which means you can provide the labels with $translateProvider.translations(). Why? Because you do not have to test the remote loading functionality which is part of angular-translate project.

回答6:

I encountered this problem with protractor tests. My solution was to mock translations like this:

angular.module('app')
        .config(function ($translateProvider) {
            $translateProvider.translations('en', {});
            $translateProvider.preferredLanguage('en');
        })

Now no language files are downloaded, no strings get translated and I just test against the string keys in specifications:

expect(element(by.css('#title')).getText()).toEqual('TITLE_TEXT');

回答7:

None of the solutions worked for me but I came with these solutions:

1) If you need to use scope.$apply(), or should deal with states in your test (after the $apply() the 2nd approach won't work), override your app's translations with the $translateProvider.translations() method, using a plugin to load JSON files

beforeEach(module(function ($translateProvider) {
    $translateProvider.translations('en', readJSON('scripts/i18n/locale-en.json'));
}));

2) If your tested controller depends on the $translate service you can use a plugin to load JSON files and combine it with $httpBackend to load your locale file when angular-translate requests it.

beforeEach(inject(function (_$httpBackend_) {
    $httpBackend = _$httpBackend_;

    $httpBackend.whenGET('scripts/i18n/locale-en.json').respond(readJSON('scripts/i18n/locale-en.json'));
    $httpBackend.flush();
})));

Note this should be below your beforeEach(module('myApp')); or you will get an $injector error.

回答8:

I made a simple mock service for $translate

$translate=function (translation) {
    return {
      then: function (callback) {
        var translated={};
        translation.map(function (transl) {
          translated[transl]=transl;
        });
        return callback(translated);
      }
    }
  };

Usage example here : https://gist.github.com/dam1/5858bdcabb89effca457

回答9:

I use this pattern.

• ApplicationModule set regular angular-translate config.
• test code load 'testModule' instead of 'applicationModule'

// application module .js 
(function() {
  'use strict'; 
  
  angular
   .module('applicationModule', [
    'ngAnimate',
    'ngResource',
    'ui.router',
    'pascalprecht.translate'
  ])
  .config(['$stateProvider', '$urlRouterProvider', '$translateProvider', '$translatePartialLoaderProvider', config]);

  function config($stateProvider, $urlRouterProvider, $translateProvider, $translatePartialLoaderProvider) {
    // set routing ... 
        
    $translateProvider.useStaticFilesLoader({
      prefix: 'i18n/locale-',
      suffix: '.json'
    });

    $translateProvider.useMessageFormatInterpolation();
    $translateProvider.fallbackLanguage(['en']);
    $translateProvider
    .registerAvailableLanguageKeys(['en', 'ko'], {
      'en_US': 'en',
      'ko_KR': 'ko'
    })
    .determinePreferredLanguage(navigator.browserLanguage);

            
    $translateProvider.addInterpolation('$translateMessageFormatInterpolation');    
    $translateProvider.useSanitizeValueStrategy('escaped');
  }

})();

// test.module.js
(function() {
  'use strict';

  angular
    .module('testModule', ['applicationModule'])
    .config(['$translateProvider', '$translatePartialLoaderProvider', config])
    .run(['$httpBackend', run]);

  function config($translateProvider, $translatePartialLoaderProvider) {
    $translateProvider.useLoader('$translatePartialLoader', {
        urlTemplate: 'i18n/locale-en.json'
    });
    $translatePartialLoaderProvider.addPart('applicationModule');
  }

  function run($httpBackend) {
    $httpBackend.when('GET', 'i18n/locale-en.json').respond(200);
  }

})();


// someDirective.spec.js
describe("a3Dashboard", function() {
    beforeEach(module("testModule"))

    var element, $scope;
    beforeEach(inject(function($compile, $rootScope) {
        $scope = $rootScope;
        element = angular.element("<div>{{2 + 2}}</div>");
        $compile(element)($rootScope)
    }))

    it('should equal 4', function() {
      $scope.$digest();
      expect(element.html()).toBe("4");
    })

})

回答10:

Late to the table with this, but I got round this by specifying that Karma simply serve the files as per this entry in karma.conf.js:

files: [
    ...
    {pattern: 'scripts/i18n/*.json', included: false, served: true},
    ...
]

回答11:

The 2016 answer for this is to preprocess your json into your tests and properly test translations work on your directives.

I use karma-ng-json2js-preprocessor. Follow all the steps to setup your karma.conf then in your test file, prepend the relevant file as a module, then set that information in $translateProvider.

beforeEach(module('myApp', '/l10n/english-translation.json'));

// Mock translations for this template
beforeEach(module(function($translateProvider, englishTranslation) {
    $translateProvider.translations('en_us', englishTranslation);
    $translateProvider.useSanitizeValueStrategy(null);
    $translateProvider.preferredLanguage('en_us');
}));

Note according to the plugin, it uses your filename to generate a camelcased module name. You can play with the function inside the module's /lib but basically it remove all dashes but KEEPS underscores in a camelCase. So en_us becomes En_us.

You'll also need to tell your test that it is expecting that file as a GEt.

    $httpBackend.expect('GET', '/l10n/english-translation.json').respond(200);