单元测试AngularJS服务

Question

我有以下AngularJS服务类，如何为该服务编写Jasmine单元测试类？

quoteApp.service('TravelInfoService', function() {
    this.travelAreaTest = function() {
        return 'TESTVAL';
    };
    this.travelAreaDiasbled = function(currentTripType) {
        if (currentTripType.substring(0, 4) == 'SING') {
            return true;
        } else {
            return false;
        }
    };
});

单元测试类

describe('sample test', function() {

var travelInfoService = null;

  beforeEach(module('quoteApp'));

  beforeEach(inject(function(TravelInfoService) {
  scope = $rootScope.$new();
  travelInfoService = TravelInfoService;

}));


it('should not be false', function() {
  expect(travelInfoService.travelAreaTest()).toEqual(false);
});

});

此单元测试类不起作用，因此需要帮助才能纠正它。