您应该如何将服务层方法划分为可测试的块？

Question

exports.sendFeedbackServiceProviderMethod = function(req, res, next) {

    var articleId = req.body.articleId
    var commentId = req.body.commentId
    var action = req.body.action
    var meta = req.body.meta

    var Target
    var targetId
    if (articleId) {
        Target = Article
        targetId = articleId
    }
    else if (commentId) {
        Target = Comment
        targetId = commentId
    }

    //1. find the target
    //Note: will refetch when need to send json, since feedback has been changed
    Target.findById(targetId).exec(function(err, target) {
        if (err)
            return next(err)
        if (!target)
            return next(helper.getGeneralError('target does not exist'))


        //2. find the feedback
        var criteria = {}
        criteria['statusMeta.createdBy'] = req.user
        if (action === 'like' || action === 'dislike' || action === 'unlike' || action === 'undislike')
            criteria['type'] = {$in: ['like', 'dislike']}
        else if (action === 'share' || action === 'unshare')
            criteria['type'] = 'share'
        if (articleId)
            criteria['target.article'] = articleId
        else if (commentId)
            criteria['target.comment'] = commentId

        Feedback.find(criteria).exec(function(err, feedbacks) {

            if (err)
                next(err)
            if (feedbacks.length === 0) {
                //3. Feedback does not exist, create it
                var newFeedback = new Feedback()

                if (action === 'like' || action === 'dislike' || action === 'share') {
                    newFeedback.type = action
                    newFeedback.status = 'normal'
                    newFeedback.statusMeta.createdBy = req.user
                    if (articleId)
                        newFeedback.target.article = targetId
                    else if (commentId)
                        newFeedback.target.comment = targetId
                    if (meta)
                        newFeedback.meta= meta
                }

                newFeedback.save(function(err) {
                    if (err)
                        return next(err)

                    //4. save to target feedbacks list
                    target.feedbacks.push(newFeedback)
                    target.save(function(err) {
                        if (err)
                            return next(err)

                        //5. save to user feedbacks list
                        req.user.feedbacks.push(newFeedback)
                        req.user.save(function(err) {
                            if (err)
                                return next(err)

                            //6. done
                            //Note: send the target!
                            //Note: refetch target and populate, since its feedbacks have been changed
                            var query = Target.findById(targetId)
                            populateUsersForQuery(query)
                            populateFeedbacksForQuery(query)
                            query.exec(function(err, target) {
                                if (err)
                                    return next(err)
                                return res.json(target)
                            })
                        })
                    })
                })
            }
            else {
                //3x. Found the feedback, update it
                var feedback = feedbacks[0] //must be length 1

                if (action === 'like' || action === 'dislike' || action === 'share') {
                    feedback.type = action
                    feedback.status = 'normal'
                    feedback.statusMeta.updatedBy = req.user
                    feedback.statusMeta.updatedDate = new Date
                }
                else if (action === 'unlike' || action === 'undislike' || action === 'unshare') {
                    feedback.status = 'deleted'
                    feedback.statusMeta.deletedBy = req.user
                    feedback.statusMeta.deletedDate = new Date
                }
                if (meta)
                    feedback.meta= meta

                feedback.save(function(err) {
                    if (err)
                        return next(err)

                    //4x. done
                    //Note: send the target!
                    //Note: refetch target and populate, since its feedbacks have been changed
                    var query = Target.findById(targetId)
                    populateUsersForQuery(query)
                    populateFeedbacksForQuery(query)
                    query.exec(function(err, target) {
                        if (err)
                            return next(err)
                        return res.json(target)
                    })
                })
            }
        })
    })
}

我有这段代码，它很大，我想知道如何进行测试。我应该将其分成较小的部分，如何做，还是应该保持原样并测试整个块。另外，我不确定测试服务层方法的标准方法是什么，我们是否像下面这样整体测试路由：

describe('POST /user', function() {
  it('user.name should be an case-insensitive match for "john"', function(done) {
    request(app)
      .post('/user')
      .send('name=john') // x-www-form-urlencoded upload
      .set('Accept', 'application/json')
      .expect(function(res) {
        res.body.id = 'some fixed id';
        res.body.name = res.body.name.toLowerCase();
      })
      .expect(200, {
        id: 'some fixed id',
        name: 'john'
      }, done);
  });
});

还是应该检查每个已修改对象的状态？您能否告诉我如何为上述方法设置单元测试，以及如何划分单元测试以简化测试？

Answer 1

您的方法sendFeedbackServiceProviderMethod承担太多违反SRP（Single Responsibility Principle）的职责。您绝对应该考虑使用Split phase technique等进行重构。完成之后，您可以独立测试功能。所有这些find，findById，update和save功能都指示不同的动作，因此可能具有不同的功能。您当然可以保留当前测试作为验收测试，并且在重构此庞大功能之后，创建适当的单元测试。