Mocking constants/values/etc. within AngularJS unit tests

var app = angular.module('plunker', []);

app.value('movieTitle', 'The Matrix');

app.controller('DemoController', function($scope, demoService) {
  $scope.name = demoService.fn3();
});

app.service('demoService', function(movieTitle) {
  this.fn3 = function() {
    return movieTitle;
  }
});

////////////////////////////////////////////////////////////////////////////////

describe('Decorating Services', function() {
  var demoService = null;
  var $provide = false;

  beforeEach(module('plunker'));

  beforeEach(function() {
    angular.mock.module(function(_$provide_) {
      $provide = _$provide_;

      $provide.decorator('movieTitle', function($delegate) {
        return ' - starring Keanu Reeves';
      });
    });

    inject(function(_$rootScope_, $injector) {
      demoService = $injector.get('demoService');
    });
  });

  it('should be able to alter a injected value', function() {
    app.value('movieTitle', 'The Matrix2');

    expect(demoService.fn3()).toEqual('');
  });

});

<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS test</title>
    <link data-require="jasmine" data-semver="2.2.1" rel="stylesheet" href="http://cdnjs.cloudflare.com/ajax/libs/jasmine/2.2.1/jasmine.css" />
    <script data-require="jasmine" data-semver="2.2.1" src="http://cdnjs.cloudflare.com/ajax/libs/jasmine/2.2.1/jasmine.js"></script>
    <script data-require="jasmine" data-semver="2.2.1" src="http://cdnjs.cloudflare.com/ajax/libs/jasmine/2.2.1/jasmine-html.js"></script>
    <script data-require="jasmine@*" data-semver="2.2.1" src="http://cdnjs.cloudflare.com/ajax/libs/jasmine/2.2.1/boot.js"></script>
    <script data-require="angular.js" data-semver="1.4.3" src="https://code.angularjs.org/1.4.3/angular.js"></script>
    <script data-require="angular-mocks" data-semver="1.4.3" src="https://code.angularjs.org/1.4.3/angular-mocks.js"></script>
    <link rel="stylesheet" href="style.css" />
    <script src="appSpec.js"></script>
    <script src="jasmineBootstrap.js"></script>
    <!-- bootstraps Jasmine -->
  </head>

  <body>
    <div id="container" ng-controller="DemoController">
      <h1>Hello {{name}}</h1>
    </div>
    <div id="HTMLReporter" class="jasmine_reporter"></div>
  </body>

</html>

(function() {
  var jasmineEnv = jasmine.getEnv();
  jasmineEnv.updateInterval = 250;

  /**
   Create the `HTMLReporter`, which Jasmine calls to provide results of each spec and each suite. The Reporter is responsible for presenting results to the user.
   */
  var htmlReporter = new jasmine.HtmlReporter();
  jasmineEnv.addReporter(htmlReporter);

  /**
   Delegate filtering of specs to the reporter. Allows for clicking on single suites or specs in the results to only run a subset of the suite.
   */
  jasmineEnv.specFilter = function(spec) {
    return htmlReporter.specFilter(spec);
  };

  /**
   Run all of the tests when the page finishes loading - and make sure to run any previous `onload` handler

   ### Test Results

   Scroll down to see the results of all of these specs.
   */
  var currentWindowOnload = window.onload;
  window.onload = function() {
    if (currentWindowOnload) {
      currentWindowOnload();
    }

    //document.querySelector('.version').innerHTML = jasmineEnv.versionString();
    execJasmine();
  };

  function execJasmine() {
    jasmineEnv.execute();
  }
})();

/* restore "body" styling that were changes by "jasmine.css"... */
body { background-color: white; padding: 0; margin: 8px; }
/* ... but remain the "jasmine.css" styling for the Jasmine reporting */
.jasmine_reporter { background-color: #eeeeee; padding: 0; margin: 0; }