Mongo Schemas - Mocha 测试时出现 Mongoose 错误（MissingSchemaError 和 OverwriteModelError）

Question

编辑 - 看来我在这里遇到了两个问题。我已接受下面给出的答案，但请阅读 cmets，因为 mocha -w 问题在修复中同样重要。

我已经阅读了一些关于此的 SO 问题和答案，并尝试了一些建议的方法，但我仍然无法解决此问题，所以我希望有人可以帮助我：

我有一个模型：

const mongoose = require('mongoose');
mongoose.Promise = global.Promise;
const slug = require('slugs');

const storySchema = new mongoose.Schema({
  name :{
    type: String,
    trim: true,
    required: 'Please enter a store name'
},
  slug: String,
  storyText: {
    type: String,
    trim:true
},
  keyStageLevel: [String]
});


module.exports = mongoose.model('Story', storySchema);

还有一个故事控制器：

const mongoose = require('mongoose');
const Story = mongoose.model('Story');

exports.storyHomePage = (req, res) => {
console.log(req.name);
res.render('story', {
    title:"Reading Project = Story Home Page",
    created:req.query.created

  });
};

我让 mocha 运行了一些测试。但是，当我运行测试时，我得到一个错误

MissingSchemaError: Schema hasn't been registered for model "Store".

阅读此https://stackoverflow.com/a/21915511/1699434 我可以将我的storyController 修改为

const mongoose = require('mongoose');

mongoose.model('Story', new mongoose.Schema());

const Story = mongoose.model('Story')

这让 Mocha 很开心，但随后 nodemon 因错误而崩溃

OverwriteModelError: Cannot overwriteStorymodel once compiled.

环顾这个https://stackoverflow.com/a/19051909/1699434 似乎是解决这个问题的方法，但据我所知，我正在使用这种方法（我使用const Store = mongoose.model('Store'); 而不是const Store = require('../models/Store')）

所以我有点卡住了。非常感谢任何帮助！

编辑以包含 start.js

const mongoose = require('mongoose');


// import environmental variables from our variables.env file
require('dotenv').config({ path: 'variables.env' });

// Connect to our Database and handle any bad connections
mongoose.connect(process.env.DATABASE);
mongoose.Promise = global.Promise; // Tell Mongoose to use ES6 promises
mongoose.connection.on('error', (err) => {
  console.error(`${err.message}`);
});

//import all of the models
require('./models/Story');

// Start app
const app = require('./app');
app.set('port', process.env.PORT || 7777);
const server = app.listen(app.get('port'), () => {
console.log(`Express running → PORT ${server.address().port}`);
});

Answer 1

您应该使用以下语法导入 Story 模型，并且无需再次导入 mongoose 模块：

// I suppose the file is located in 'models' folder and the current folder is 'controllers'
const Story = require('../models/story');

通过const Story = mongoose.model('Story');，您正在创建一个没有模式定义的故事模型，这就是您获得Schema hasn't been registered for model "Store". 的原因

在你的第二个例子中：

// this create a new model from an empty schema (schema without fields)
mongoose.model('Story', new mongoose.Schema());

// overwriting the first model which is not allowed by mongoose
const Story = mongoose.model('Story')

请记住，mongoose.model() 方法仅从映射到 MongoDB 集合的模式定义模型