Getting this error "Error: beforeEach expects a function argument; received [object Object]" while testing angularjs using karma and jasmine

I am getting this error "Error: beforeEach expects a function argument; received [object Object]" while testing angularjs using karma and jasmine. I have tried in so many ways but couldn't get the solution. I have given below my spec code and karma conf js. For your information I do use requirejs in my application due to some dependencies

//Service Spec code :
define([], function () {
  'use strict';
  describe('search Service spec', function () {
    var searchService;   
    beforeEach(angular.module('flightRouteApp', []));    
    describe('service methods', function () {
      it('should calculate the length of the element', inject(function (searchService) {
        expect(searchService).toBeDefined();
      }));
    });
  });
});

// Karma configuration
// Generated on Sun Mar 05 2017 09:17:46 GMT+0100 (W. Europe Standard Time)
/* global module */
"use strict";
module.exports = function (config) {
config.set({
  // base path that will be used to resolve all patterns (eg. files, exclude)
  basePath: '',

  // frameworks to use
  // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
  frameworks: ['jasmine','requirejs'],

  // list of files / patterns to load in the browser
  files: [
    {pattern:'node_modules/angular/angular.js',watched: true, included: true, served: true},
    {pattern:'node_modules/angular-mocks/angular-mocks.js',watched: true, included: true, served: true},
    {pattern:'app/js/flightRoute.js',watched: true, included: true, served: true},
    {pattern:'app/js/services/*.js',watched: true, included: true, served: true},
    {pattern:'app/js/**/*.js',watched: true, included: true, served: true},
    {pattern:'tests/test-main.js',watched: true, included: true, served: true},
    {pattern: 'tests/**/*.Spec.js',watched: true, included: true, served: true}
  ],

  // list of files to exclude
  exclude: [ ],

  // test results reporter to use
  // possible values: 'dots', 'progress'
  // available reporters: https://npmjs.org/browse/keyword/karma-reporter
  /*reporters: ['progress','coverage'],*/
  reporters: config.angularCli && config.angularCli.codeCoverage
           ? ['progress', 'coverage-istanbul']
           : ['progress', 'kjhtml'],
  preprocessors: {
    'app/js/**/*.js': 'coverage'
  },

  // web server port
  port: 9876,
  coverageReporter: {includeAllSources: true, reporters:[{type: 'html', dir:'coverage/'}]},

  // enable / disable colors in the output (reporters and logs)
  colors: true,
  //vel of logging
  // possible values: config.LOG_DISABLE || config.LOG_ERROR || 
  config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
  logLevel: config.LOG_INFO,

  // enable / disable watching file and executing tests whenever any file changes
  autoWatch: false,

  // start these browsers
  // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
  browsers: ['Chrome'],

  // Continuous Integration mode
  // if true, Karma captures browsers, runs the tests and exits
  singleRun: false,

  // Concurrency level
  // how many browser should be started simultaneous
  concurrency: Infinity
  })
}