为什么会出现错误“编译后无法覆盖模型"?当我第二次进行测试时，在猫鼬中? [英] Why do I get error "Cannot overwrite model once compiled" in Mongoose when I run my test a second time?

问题描述

我已阅读相关文章:一旦编译过猫鼬，就无法覆盖模型

这些解决方案都不能解决我的问题.

Problem is neither of these solution's helped me with my problem.

我得到标题错误，并且进行了以下设置:

I get the error in the title and I have following setup:

文件夹结构:

我的模型如下:

forums.js

forums.js

const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const topicGroupSchema = require("./topicGroups");

const forumSchema = new Schema({
    title: String,
    topicGroups: [topicGroupSchema]
})

const Forum = mongoose.model("forums", forumSchema);

module.exports = Forum;

topicGroups.js

topicGroups.js

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const topicGroupSchema = new Schema({
    title: String,
   // Todo: add topics
})

module.exports = topicGroupSchema;

我的test_helper和saveForum_test.js文件如下:

My test_helper and saveForum_test.js files look like this:

saveForum_test.js

saveForum_test.js

const assert = require("assert");
const Forum = require("../model/forums")

describe("Creating records", () => {
    it("can save a new forum", (done) => {
        const forum = new Forum({
            title: "CodeHUB"
        })
        forum.save()
            .then(() => {
                assert(forum.isNew)
                done();
            })
    })
})

test_helper.js

test_helper.js

const mongoose = require("mongoose");
mongoose.Promise = global.Promise;

before(done => {
    mongoose.connect("mongodb://myuser:[e-mail]:21339/clicker", { useNewUrlParser: true });
    mongoose.connection
        .once("open", () => {done()})
        .on("error", error => {
            console.warn("error", error)
        })
})

// FIXME: error when saved twice

beforeEach(done => {
    console.log(mongoose.connection.collections.forums)
    mongoose.connection.dropCollection("forums", () => {
        done();
    })
})

因此，当我使用Mocha运行测试套件时，一切都会按预期进行. 但是，当我更改某些内容并再次运行时，出现错误

So when I run my test suite with mocha, everything works as expected. But when I change something, and run it again, I get the error

OverwriteModelError:编译后无法覆盖forums模型.

我将mlab与mongoose一起使用，而不是在本地安装的mongodb.也许与此有关吗?我想不通，我检查了所有文件和导入文件等10次，找不到错误，可以吗?

I use mlab with mongoose and not a local installed mongodb. Maybe it has something todo with that? I can't figure it out, I checked all the files and imports etc. 10 times and can't find a mistake, can you ?

推荐答案

我已经解决了这个问题.

I have solved the problem.

原来的问题是我如何运行测试套件. 我在package.json中的npm run test命令执行了以下操作:

Turns out the problem was how I was running my test suite. My npm run test command in package.json did the following:

"test": "mocha --watch"

这是错误.我认为--watch不能重新实例化所有内容，就像热模块更换"一样.

Here was the error. I think --watch doesn't reinstantiate everything and is just like "Hot Module Replacement".

我安装了nodemon并更改了测试脚本，如下所示:

I installed nodemon and changed my test script like this:

"test": "nodemon --exec \"mocha -R min\""

这确保了重新运行整个文件，并且没有出现错误.

This makes sure to rerun the whole files and no error is showing up.

另一个应该起作用的相关帖子: mocha --watch和mongoose模型

Another related post that should work: mocha --watch and mongoose models

这篇关于为什么会出现错误“编译后无法覆盖模型"?当我第二次进行测试时，在猫鼬中?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！