如何在没有setTimeout的情况下使用异步Mocha before()初始化? [英] How to use async mocha before() initialization without setTimeout?

问题描述

我正在使用Mocha来测试我创建的一些数据库查询.我需要在block之前创建适当的外键，以便单元测试可以专注于测试Node ORM的原始创建/删除功能.

I am using Mocha to test out some database queries I created. I need my before block to create the appropriate foreign keys so the unit tests can focus on testing out the raw create/delete functionality of my Node ORM.

我的问题是我在before块中插入db条目，并且单元测试在before块完成执行之前正在运行.

My problem is that I am inserting db entries in my before block and the unit tests are running before the before block is finished executing.

我读到了应使用promise处理这类事情，因此我重构了代码库以使用promise，但仍然无法绕开我需要setTimeout的事实.

I read that promises should be used to deal with this kind of thing, so I refactored my codebase to use promises but I still can't get around the fact that I need a setTimeout.

如何执行异步before块而无需将我的第一个it块包装在setTimeout中?

How can I perform async before block without needing to wrap my first it block in a setTimeout?

var chai = require('chai');
var expect = chai.expect;
var db = require('../server/db/config');
var models = require('../server/db/models');

describe('scoring', function() {

  var testMessage = {
    x: 37.783599,
    y: -122.408974,
    z: 69,
    message: 'Brooks was here'
  };

  var messageId = 1;

  before(function() {
    var token = '' + Math.random();
    models.createUser(token).then(function() {
      testMessage.userToken = token;
      models.insert(testMessage)
    });
  });

  it('should have votes created in db when createVote is called', function(done) {
    setTimeout(function(done) {
      models.createVote(messageId, token, function(err, res) {
        expect(res.insertId).to.be.a('number');
        done();
      });
    }.bind(this, done), 1000);
  });
});

推荐答案

您可以像乔伊斯建议那样进行操作.但是，Mocha支持使用诺言进行同步.您必须兑现您的诺言:

You could do it like joews suggests. However, Mocha supports using promises for synchronization. You have to return your promise:

before(function() {
    var token = '' + Math.random();
    return models.createUser(token).then(function() {
      testMessage.userToken = token;
      models.insert(testMessage)
    });
});

在能够对代码返回的诺言执行.then之前，Mocha不会继续进行测试.

Mocha won't continue to the test until it is able to execute .then on the promise returned by your code.

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