What is the best way to pass a mock object between multiple test files in karma?

Question

What is the best way to pass a mock object between multiple test files in karma?

Currently, I am working on an Angular application that has multiple test files sharing the same mocks. I am looking for a way to extract these mocks and store them in a separate file.

Initially, I attempted to create an object and reuse it in my tests, but encountered an exception: ReferenceError: Can't find variable: require

Below is my Karma file configuration:


// Karma file configuration
module.exports = {
  options: {
    frameworks: ['jasmine'],
    preprocessors: {
      '<%= paths.scripts %>/**/*.js': ['coverage']
    },
    reporters: ['progress', 'coverage', 'junit'],
    coverageReporter: {
      dir : '<%= paths.coverage %>',
      reporters: [
        { type: 'html', subdir: 'report-html' },
        { type: 'cobertura', subdir: '.', file: 'code-coverage.xml' },
      ]
    },
    junitReporter: {
      outputFile: '<%= paths.testReport %>/test-results-karma.xml'
    },
    port: 9999,
    colors: true,
    logLevel: 'INFO',
    autoWatch: false,
    browsers: ['PhantomJS'],
    singleRun: true
  },

  portal: {
    // Additional configuration for portal
    options: {
      basePath: 'public/',
      files: [
        'bower_components/angular/angular.js',
        'bower_components/angular-mocks/angular-mocks.js',
        'bower_components/angular-sanitize/angular-sanitize.js',
        'bower_components/angular-bootstrap/ui-bootstrap.js',
        'bower_components/angular-translate/angular-translate.js',
        'bower_components/angular-translate-loader-static-files/angular-translate-loader-static-files.js',
        'scripts/<%= paths.module %>',
        'scripts/**/*.js',
        'test/mock/**/*.js',
        'test/spec/unit/**/*.js'
      ]
    }
  }
};

Here is the mock code snippet:


var EcMock = (function() {
  'use strict';

  function ecMock() {
    this.dom = {
      addClass: function() {
        return angular.noop();
      },
      getViewportWidth: function() {
        return angular.noop();
      }
    };

    this.detect = {
      geolocation: true
    };
  }

  return ecMock;
})();

module.exports = EcMock;

Usage of the mock in Karma test file:


var EcMock = require('../../../../mock/EcMock');

javascript angularjs unit-testing karma-jasmine

Answer 1

Answer №1

Discovering the solution to this issue using an angular approach has been enlightening. The detailed comments provide a step-by-step guide on how to proceed.

//To begin, ensure your mock files are included in the karm conf file

//Next, establish a mock service
(function() {
'use strict';

angular.module('mock')
  .factory('myServiceMock', myServiceMock);
  
  function myServiceMock($q) {   
    var methodsToMock = ['myMethod1', 'myMethod2'],
        service = {};
    
    //Create an object with pre-defined spies using one of the two approaches below:
    
    //Approach 1: simple methods
    service = jasmine.createSpyObj('myServiceMock', methodsToMock]); 
    
    //Approach 2: promise methods
    angular.forEach(methodsToMock, function(method) {
      service[method] = jasmine.createSpy(method).and.returnValue($q.when({}));
    }); 
    
    return service;
  }
})();

//Then, utilize the mock service
(function() {
'use strict';

describe('Service Test', function() {
  var myServiceMock;
  
  //Load mock module
  beforeEach(module('mock'));

  beforeEach(inject(function(_myServiceMock_) {
    //Retrieve mock service
    myServiceMock = _myServiceMock_;
  }));
  
  describe('Feature Test', function() {
  
    it('should test something', function() {
      //Customize the return value of your mock method
      myServiceMock.method1.and.returnValue('Return some value');
    });
  });
});
})();

//Remember to instruct angular to use your mock service instead of the actual one.

//For testing a controller:
beforeEach(inject(function(_$controller_, _myServiceMock_) {
    scope = _$rootScope_.$new();
    myServiceMock = _myServiceMock_;

    MyController = _$controller_('MyController', {
      $scope: scope,
      myServiceMock: myServiceMock //Utilize mock service over real one
    });
  }));

//For testing another service:
beforeEach(function () {
  module(function($provide) {
    $provide.service('myService', myServiceMock);
  });
});

Answer 2

Discovering the solution to this issue using an angular approach has been enlightening. The detailed comments provide a step-by-step guide on how to proceed.

//To begin, ensure your mock files are included in the karm conf file

//Next, establish a mock service
(function() {
'use strict';

angular.module('mock')
  .factory('myServiceMock', myServiceMock);
  
  function myServiceMock($q) {   
    var methodsToMock = ['myMethod1', 'myMethod2'],
        service = {};
    
    //Create an object with pre-defined spies using one of the two approaches below:
    
    //Approach 1: simple methods
    service = jasmine.createSpyObj('myServiceMock', methodsToMock]); 
    
    //Approach 2: promise methods
    angular.forEach(methodsToMock, function(method) {
      service[method] = jasmine.createSpy(method).and.returnValue($q.when({}));
    }); 
    
    return service;
  }
})();

//Then, utilize the mock service
(function() {
'use strict';

describe('Service Test', function() {
  var myServiceMock;
  
  //Load mock module
  beforeEach(module('mock'));

  beforeEach(inject(function(_myServiceMock_) {
    //Retrieve mock service
    myServiceMock = _myServiceMock_;
  }));
  
  describe('Feature Test', function() {
  
    it('should test something', function() {
      //Customize the return value of your mock method
      myServiceMock.method1.and.returnValue('Return some value');
    });
  });
});
})();

//Remember to instruct angular to use your mock service instead of the actual one.

//For testing a controller:
beforeEach(inject(function(_$controller_, _myServiceMock_) {
    scope = _$rootScope_.$new();
    myServiceMock = _myServiceMock_;

    MyController = _$controller_('MyController', {
      $scope: scope,
      myServiceMock: myServiceMock //Utilize mock service over real one
    });
  }));

//For testing another service:
beforeEach(function () {
  module(function($provide) {
    $provide.service('myService', myServiceMock);
  });
});

What is the best way to pass a mock object between multiple test files in karma?

Answer №1

Similar questions

Leveraging Selenium to extract text from a dynamically populated DIV using JavaScript

Is there a way to update the background image of a div element through a JavaScript file within a react component?

Installation of MongoDB's Node.js Driver has encountered a failure

The shadows in three.js vary across various versions

Is the max and min-width being properly set by the keen-slider__slide class in keen-slider?

Slide feature in Drupal Views allows you to create dynamic

Using Jquery to tally the number of JSON elements

Having issues with the functionality of AngularJS material's md-checkbox

There seems to be a lack of response from the Foursquare API in Node.js

Monitor the $scope within a factory by utilizing the $http service in AngularJS

To prevent a JavaScript or jQuery method from affecting an anchor tag, assign a specific value to its href attribute

Generate a new document and input information using the ionic framework

Tips for Updating HTML Table Content Dynamically Using JavaScript without jQuery

During events, the Angular JS scope variable seems to be inaccessible

Getting a Next.js error after performing a hard refresh on a page that contains a dynamic query

Creating distinct short identifiers across various servers

PHP child categories causing jQuery menu loading issue

Converting RowDataPacket to an array in Node.js and MySQL API, learn how to convert a RowDataPacket from the MySQL API into an array

Determine the number of occurrences of specific values within a group of objects based on a

What are the best methods for authenticating and authorizing Angular get and post requests within AspNetCore 2.2?