javascript - 使用 mocha 返回 promise 的测试方法调用

Question

我是 Mocha 的新手，但我读到他们现在支持 promise，但我似乎找不到任何可以解决我的问题的文档。我有一个返回 promise 的身份验证方法。在我的测试中，我需要等到完成才能通过/失败。

这是我的身份验证工厂:

(function() {
'use strict';

angular.module('app.authentication').factory('authentication', authentication);

/* @ngInject */
function authentication($window, $q, $location, authenticationData, Session) {
    var authService = {
        authenticate: authenticate
    };

    return authService;

    function authenticate() {
        var token = authenticationData.getToken();
        var deferral = $q.defer();
        if (!Session.userId && token) {
            authenticationData.getUser(token).then(function(results) {
                Session.create(results.id, results.userName, results.role);
                deferral.resolve();
            });
        }
        else{
            deferral.resolve();
        }

        return deferral.promise;
    }.........

这是我的测试:

describe('authentication', function() {

    beforeEach(function() {
        module('app', specHelper.fakeLogger);
        specHelper.injector(function($q, authentication, authenticationData, Session) {});
    });

    beforeEach(function() {
        sinon.stub(authenticationData, 'getUser', function(token) {
            var deferred = $q.defer();
            deferred.resolve(mockData.getMockUser());
            return deferred.promise;
        });
    });

    describe('authenticate', function() {
        it('should create Session with userName of TestBob', function() {
            authentication.authenticate().then(function(){
                console.log('is this right?');
                expect(Session.userName).to.equal('TesaatBob');
            }, function(){console.log('asdfasdf');});
        });
    });
});

当我运行它时，测试通过了，因为它从未在 promise 中实现并且从未达到预期。如果我输入“return authenication.authenticate ....”，那么它会因超时而出错。

谢谢

Answer 1

直到下一个摘要周期，Angular promises 才会得到解决。

参见 http://brianmcd.com/2014/03/27/a-tip-for-angular-unit-tests-with-promises.html :

One thing that you'll quickly run into when unit testing Angular applications is the need to hand-crank the digest cycle in certain situations (via scope.$apply() or scope.$digest()). Unfortunately, one of those situations is promise resolution, which is not very obvious to beginning Angular developers.

我相信添加一个 $rootScope.$apply() 应该可以解决您的问题并强制执行 promise 解析，而无需进行异步测试。