nodemon , app crashed , waiting for file changes before starting

Question

I'm trying to make a to-do app with node.js and mongodb to store the info that users input to the database, but im not sure whats going on. I keep getting this error when i try to run nodemon. I'm new to node.js so maybe i missed something? The code below is server.js.

let express = require('express')
let mongodb = require('mongodb')

let app = express()
let db 

let connectionString = 'mongodb+srv://todoAppUser:Se@ttle1@cluster0.iod2u.mongodb.net/ToDoApp?retryWrites=true&w=majority'
mongodb.connect(connectionString, {useNewUrlParser: true, useUnifiedTopology: true}, function(err, client){
  db = client.db()
  app.listen(3000)
})

app.use(express.urlencoded({extended: false}))

app.get('/', function(req, res) {
  db.collection('items').find().toArray(function(err.items){
    console.log('items')
  })
    res.send(`<!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>Simple To-Do App</title>
      <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" integrity="sha384-GJzZqFGwb1QTTN6wy59ffF1BuGJpLSa9DkKMp0DgiMDm4iYMj70gZWKYbI706tWS" crossorigin="anonymous">
    </head>
    <body>
      <div class="container">
        <h1 class="display-4 text-center py-1">To-Do App</h1>
        
        <div class="jumbotron p-3 shadow-sm">
          <form action="/create-item" method="POST" >
            <div class="d-flex align-items-center">
              <input name="item" autofocus autocomplete="off" class="form-control mr-3" type="text" style="flex: 1;">
              <button class="btn btn-primary">Add New Item</button>
            </div>
          </form>
        </div>
        
        <ul class="list-group pb-5">
          <li class="list-group-item list-group-item-action d-flex align-items-center justify-content-between">
            <span class="item-text">Fake example item #1</span>
            <div>
              <button class="edit-me btn btn-secondary btn-sm mr-1">Edit</button>
              <button class="delete-me btn btn-danger btn-sm">Delete</button>
            </div>
          </li>
          <li class="list-group-item list-group-item-action d-flex align-items-center justify-content-between">
            <span class="item-text">Fake example item #2</span>
            <div>
              <button class="edit-me btn btn-secondary btn-sm mr-1">Edit</button>
              <button class="delete-me btn btn-danger btn-sm">Delete</button>
            </div>
          </li>
          <li class="list-group-item list-group-item-action d-flex align-items-center justify-content-between">
            <span class="item-text">Fake example item #3</span>
            <div>
              <button class="edit-me btn btn-secondary btn-sm mr-1">Edit</button>
              <button class="delete-me btn btn-danger btn-sm">Delete</button>
            </div>
          </li>
        </ul>
        
      </div>
      
    </body>
    </html>`)
})

app.post('/create-item', function(req, res){
    db.collection('items').insertOne({text: req.body.item},
      function(){
        res.send("thanks for submitting the form")
      })
})

Here is package.json, where the nodemon file is

{
  "name": "todo-app",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "watch": "nodemon server",
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node server.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1",
    "mongodb": "^3.6.4",
    "nodemon": "^2.0.7"
  }
}

and here is the error in the terminal.

npm run watch

> todo-app@1.0.0 watch C:\Users\jasmi\OneDrive\Documents\todo-app     
> nodemon server

[nodemon] 2.0.7
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node server.js`
C:\Users\jasmi\OneDrive\Documents\todo-app\server.js:16
  db.collection('items').find().toArray(function(err.items){
                                                    ^

SyntaxError: Unexpected token '.'
    at wrapSafe (internal/modules/cjs/loader.js:979:16)
    at Module._compile (internal/modules/cjs/loader.js:1027:27)       
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)  
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
    at internal/main/run_main_module.js:17:47
[nodemon] app crashed - waiting for file changes before starting...

pkumar · Answer 1 · 2021-03-02T04:58:06.743

1

C:\Users\jasmi\OneDrive\Documents\todo-app\server.js:16 db.collection('items').find().toArray(function(err.items){

SyntaxError: Unexpected token '.'

This is the error in your code. You cannot use '.' when defining function arguments. Also you're using err.items but err had not been defined anywhere

edited Mar 02 '21 at 04:58

answered Mar 02 '21 at 04:49

pkumar

79
4

score 1 · Answer 2 · answered Mar 02 '21 at 04:59

In toArray function, there are 2 arguments, first is error (err) and second is the resultant array (items). You have to replace '.' with ',' for separation between both the arguments with a comma.

Here is the correct snippet of code inside your app.get:

db.collection('items').find().toArray(function(err,items){
  if (err){
    return err;
  }
  else{
    console.log('items',items);
  }
})

Do this and you are good to go.

nodemon , app crashed , waiting for file changes before starting

2 Answers2