Siguiendo la guía oficial enangularJS $ httpBackend Haré esta prueba, pero Karma me da estoerror: Error: No pending request to flush ! at Function.$httpBackend.flush

Prueba

'use strict';

describe('profileCtrl', function () {
var scope, $httpBackend;

beforeEach(angular.mock.module('maap'));
beforeEach(angular.mock.inject(function($rootScope, $controller, _$httpBackend_){

    $httpBackend = _$httpBackend_;
    $httpBackend.when('GET', 'profile').respond([{id: 1, name: 'Bob'}]);
    scope = $rootScope.$new();
    $controller('profileCtrl', {$scope: scope});
}))

it('should fetch list of users', function(){
    $httpBackend.flush();
    expectGET(scope.current_user.length).toBe(1);
    expect(scope.current_user[0].name).toBe('Bob');
});

});

por este simplecontrolador:

'use strict';

 angular.module('maap').controller('profileCtrl', function($scope, UserService) {

$scope.current_user = UserService.details(0);

});