mocha 异步测试超时

Question

您好，我是使用 Mocha 进行测试的新手，更不用说异步测试了。运行此测试时，我不断收到以下错误。我花了很多时间在网上研究解决方案，但没有运气。

错误：超过 2000 毫秒的超时。对于异步测试和钩子，确保调用“done()”；如果返回一个 Promise，请确保它解析。

it('Should fail to create new user due to missing email', (done) => {
  const user_empty_email = {
    name: "First Name",
    email: "",
    password: "password",
    isAdmin: false
  }
  chai.request(app).post('/v1/users')
    .send(user_empty_email)
    .then((res) => {
      expect(res).to.have.status(400);
      done();
    }).catch(done)
})

以下是我收到的 /v1/users 响应示例

{
  "user": {
      "_id": "5de4293d3501dc21d2c5293c",
      "name": "Test Person",
      "email": "testemail@gmail.com",
      "password": "$2a$08$8us1C.thHWsvFw3IRX6o.usskMasZVAyrmccTNBjxpNQ8wrhlBt6q",
      "isAdmin": false,
      "tokens": [
          {
              "_id": "5de4293d3501dc21d2c5293d",
              "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJfaWQiOiI1ZGU0MjkzZDM1MDFkYzIxZDJjNTI5M2MiLCJpYXQiOjE1NzUyMzM4NTN9.mi4YyYcHCvdYrl7OuI5eDwJ8xQyKWDcqgKsXRYtn0kw"
          }
      ],
      "__v": 1
  },
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJfaWQiOiI1ZGU0MjkzZDM1MDFkYzIxZDJjNTI5M2MiLCJpYXQiOjE1NzUyMzM4NTN9.mi4YyYcHCvdYrl7OuI5eDwJ8xQyKWDcqgKsXRYtn0kw"
}

Answer 1

为什么不尝试增加超时时间（毫秒），测试运行缓慢是正常的，尤其是在测试网络请求时。

package.json

"test": "mocha --timeout 10000"

Answer 2

您的端点是否有可能实际运行超过 2 秒？如果是这样，您可能希望在运行 Mocha 时增加超时时间：Change default timeout for mocha。

另外，您的端点是否返回响应？如果没有，增加超时将无济于事。您能否将/v1/users 端点的代码添加到您的问题中以研究这种可能性？

Answer 3

对此不确定。但据我回忆，混合 Promises 和回调样式 (done-callback) 可能会在 mocha 中导致此类问题。

尝试仅使用 Promise：

• 从测试中删除所有done
• 其实是return承诺（return chai.request...）

Answer 4

问题是这个测试： mongoDB-connect.js

它在其他人之前运行。 mongoDB 连接被关闭，导致其他测试超时。当我删除关闭命令时，所有测试都按预期通过。

"use strict";
// NPM install mongoose and chai. Make sure mocha is globally
// installed
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const chai = require('chai');
const expect = chai.expect;
// Create a new schema that accepts a 'name' object.
// 'name' is a required field
const testSchema = new Schema({
  name: { type: String, required: true }
});

// mongoose connect options
var options = {
    useNewUrlParser: true,
    useUnifiedTopology: true
}

//Create a new collection called 'Name'
const Name = mongoose.model('Name', testSchema);
describe('Database Tests', function() {
  //Before starting the test, create a sandboxed database connection
  //Once a connection is established invoke done()
  before(function (done) {    
    // mongoose.connect('mongodb://localhost:27017',options);
    mongoose.connect('mongodb://ip/testDatabase',options);
    const db = mongoose.connection;
    db.on('error', console.error.bind(console, 'connection error'));
    db.once('open', function() {
      console.log('We are connected to test database!');
      done();
    });
  });
  describe('Test Database', function() {
    //Save object with 'name' value of 'Mike"
    it('New name saved to test database', function(done) {
      var testName = Name({
        name: 'Mike'
      });

      testName.save(done);
    });
    it('Dont save incorrect format to database', function(done) {
      //Attempt to save with wrong info. An error should trigger
      var wrongSave = Name({
        notName: 'Not Mike'
      });
      wrongSave.save(err => {
        if(err) { return done(); }
        throw new Error('Should generate error!');
      });
    });
    it('Should retrieve data from test database', function(done) {
      //Look up the 'Mike' object previously saved.
      Name.find({name: 'Mike'}, (err, name) => {
        if(err) {throw err;}
        if(name.length === 0) {throw new Error('No data!');}
        done();
      });
    });
  });
  //After all tests are finished drop database and close connection
  after(function(done){
    mongoose.connection.db.dropDatabase(function(){
      mongoose.connection.close(done);
    });
  });
});