Angularjs 承诺在单元测试中未得到解决

AngularJS 承诺在单元测试中未得到解决

javascript
// 服务代码
app.service('userService', function($http, $q) {
  this.getUser = function(userId) {
    var deferred = $q.defer();
    $http.get('/api/users/' + userId).then(function(response) {
      deferred.resolve(response.data);
    }, function(error) {
      deferred.reject(error);
    });
    return deferred.promise;
  };
});
// 单元测试代码
describe('userService', function() {
  var userService, $httpBackend;
  beforeEach(module('app'));
  beforeEach(inject(function(_userService_, _$httpBackend_) {
    userService = _userService_;
    $httpBackend = _$httpBackend_;
    $httpBackend.whenGET('/api/users/1').respond({ id: 1, name: 'John' });
  }));
  afterEach(function() {
    $httpBackend.verifyNoOutstandingExpectation();
    $httpBackend.verifyNoOutstandingRequest();
  });
  it('should return the correct user', function() {
    var user;
    userService.getUser(1).then(function(response) {
      user = response;
    });
    $httpBackend.flush();
    expect(user).toEqual({ id: 1, name: 'John' });
  });
});