I am creating a simple blog backend (API).

I tried creating a router and now I have an issue that I don't understand how to debug.

This is the router.

const express = require('express');
const Article = require('../models/Article')
let router = express.Router();
const app = require('../app');


router.get('/:articleId', (req,res) => {
    Post.findOne({_id : req.params.articleId})
    .then(doc => {
        if(!doc) res.send('No such post in DB')
        res.send(doc).sendStatus(200)
    })
    .catch(err => res.send({'error' : `you got some error - ${err}`}).sendStatus(400))
})

router.post('/', app.auth, async (req,res)=>{
    if(req.auth) {
        const doc = await User.findOne({uname : req.user});
        const article = {
            authorId : doc._id,
            article : {
                title : req.body.title,
                content : req.body.article
            },
            tags : req.body.tags
        }
        const newArticle = new Article(article)
        const savedArticle = await newArticle.save()
        res.send(savedArticle)
    }
    else {
        res.redirect('./login')
    }
    //if(localStorage.token) verify(token) get the userId and post the article with authorId = userId
    //if (not verified) redirect to the login page
    //get to know the jwt tokens
})

module.exports = { router };

This is the index file app.js. Just the part with the issue. And there is auth which I am exporting and is working fine within the app.js.

const express = require('express');
const mongoose = require('mongoose');
const app = express();
const env = require('dotenv').config();
const article = require('./routes/article')

app.use(express.json());
app.use(express.urlencoded({extended : true}));

mongoose.connect(process.env.MONGO_URL, {
    useNewUrlParser: true,
    useUnifiedTopology : true
}).then(() => {
    console.log("Successfully connected to the database");    
}).catch(err => {
    console.log('Could not connect to the database. Exiting now...', err);
    process.exit();
})

app.use("/article", article)
module.exports = {auth}

app.listen(port, ()=>{console.log(`Server running at port ${port}`)});

And this is the Model for Article

const mongoose = require('mongoose');

const Article = new mongoose.Schema({
    authorId : {
        type : String,
        required :true,
        default : "anonymous"
    },
    article : {
        title : {
            type : String,
            required : true
        },
        content : {
            type : [String],
            required : true
        },
        imgFiles : [String]
    },
    like : Number,
    starred : Number,
    date : {
        type : Date,
        required : true,
        default : Date.now()
    },
    tags : [String]
})

module.exports = mongoose.model('Article', Article)

And this is the error

Thanks in Advance.

CodePudding user response：

The issue is being caused because you are importing article.js into app.js and then importing the app.js into article.js creating a circular dependency. Remove that module.exports = {auth} from app.js. Note that you haven't even declared the auth function. You you should create the auth function in another file and import it into article.js.

Also this line module.exports = { router }; should just be module.exports = router;

auth.js

function auth(req, res, next) {
  // IMplementation
}
module.exports = auth

article.js

const express = require('express');
let router = express.Router();
const auth = require('./auth');


router.get('/:articleId', (req,res) => {
    res.send('article')
})

router.post('/', auth, async (req,res)=>{
    res.send('response')
})

module.exports = router;

app.js

const express = require('express');
const app = express();
const article = require('./article')

app.use(express.json());
app.use(express.urlencoded({extended : true}));

app.use("/article", article)

app.listen(3000, ()=>{console.log(`Server running at port 3000`)});

CodePudding user response：

I was making a simple mistake.

I was doing this.

module.exports = { router }

instead of

module.exports = router