Angular controller test using mocha.

controller.test.js

describe('My controller', function () {
  var scope, createController;
  
  beforeEach(module('app.controllers'));
  
  beforeEach(inject(function ($injector) {
    var $rootScope = $injector.get('$rootScope');
    var $controller = $injector.get('$controller');
    
    scope = $rootScope.$new();
    
    createController = function () {
      return $controller('CustomCtrl', {$scope: scope});
    };
  }));
  
  afterEach(function () {
    scope.$destroy();
  });
});

Where did you define "inject" and "module"?