JavaScript NodeJs - How to refactor this bit - javascript

So I am in a middle of creating a simple CRUD application, but I stumbled with getting MongoDB auto-incrementing value of latest created account.
To be more specific, I have written the tidbit below to enable the following:
1) When registering, do some validation checks
2) Check what was the latest account number, increment by 1
3) Create a new user, add to the DB
Now, if you see below, I've marked three EXHIBITS
1 & 2) For some odd reason, if I remove the code from the route itself, then it stops working properly, but I have no idea how to get rid of repeating code since the functions are pretty much identical, but removing either of those just breaks the sequence. How can I fix this and make my code neater?
3) How would I go about extracting this function into a separate one? After fiddling with this, I only get to the point where "accountNumber is not defined".
const getLastAccountNumber = function() {
User.find({}, { accountNumber: 1, _id: 0 }) **// EXHIBIT 1**
.sort({ accountNumber: -1 })
.limit(1)
.then(function(doc) {
if (!doc) throw new Error("Error?");
accountNumber = doc[0].accountNumber;
return doc[0].accountNumber;
});
};
// TODO: Refactor methods
router.post(
"/register",
[check("email").isEmail(), check("password").isLength({ min: 4 })],
function(req, res) {
User.find({}, { accountNumber: 1, _id: 0 }) **// EXHIBIT 2**
.sort({ accountNumber: -1 })
.limit(1)
.then(getLastAccountNumber())
.then(function() { **// EXHIBIT 3**
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(422).json({ errors: errors.array() });
}
const { email, password } = req.body;
const amount = 0;
accountNumber++;
const user = new User({
email,
password,
accountNumber,
amount
});
user.save(function(err) {
if (err) {
console.log(err);
res.status(500).send("Error registering new user");
} else {
res.status(200).send("User successfully added");
}
});
});
}
);
Really appreciate any feedback!

Relating to your error, I believe defining the variable by adding let accountNumber; to the top of the file might be enough to get your code working, (though I do not believe it to be a great solution...), though as you asked about refactoring:
embracing promises: Imagine a water/data flowing through a series of pipes, and in each step, the data can be transformed. Keeping this linear flow often makes the code clean and easy to follow. If any error happens on the way, all pipes until "catch" are bypassed.
if an error occurs and we get straight to "catch", we might want to handle the situation differently depending on the failure reason. Thus, we can add error wrappers like ValidationError to check for.
furthermore, we can name the pipes properly, like getNewAccountNumber, which will work even when there are no accounts in the db
arrow functions are nice
// error handling
class ValidationError {
constructor (errors) {
this.errors = errors
}
}
const checkValidation = (req, res)=> {
const errors = validationResult(req)
return errors.isEmpty()
? Promise.resolve()
: Promise.reject(ValidationError(errors.array()))
}
const successResponse = (req, res, data)=> ()=> res.status(200).send(data)
const errorResponse = (req, res, message = 'Internal Server Error')=> error=>
error instanceof ValidationError ? res.status(422).json({ errors: error.errors })
: (console.error(error), res.status(500).send(message))
// utils
const initialAccountNumber = 0
const getNewAccountNumber = ()=> User
.find({}, { accountNumber: true, _id: false })
.sort({ accountNumber: -1 })
.limit(1)
.then(xs=> !xs || !xs.length
? initialAccountNumber
: xs[0].accountNumber + 1)
// route
router.post('/register', [
check('email').isEmail(),
check('password').isLength({ min: 4 })
], (req, res)=> checkValidation(req, res)
.then(getNewAccountNumber)
.then(newAccountNumber=> {
const { email, password } = req.body
return new User({
email,
password,
accountNumber: newAccountNumber,
amount: 0,
})
})
.then(user=> user.save())
.then(successResponse(req, res, 'User successfully added'))
.catch(errorResponse(req, res, 'Error registering new user'))
)
Anyhow, I would prefer to do this as one transaction, if possible by using existing db-build-in solutions (eg. the _id is already "guaranteed" to be unique, the accountNumber using this solution not as much).

You can do something like this:
const getLastAccountNumber = function() {
return User.find({}, { accountNumber: 1, _id: 0 })
.sort({ accountNumber: -1 })
.limit(1)
.then(function(doc) {
if (!doc) throw new Error("Error?");
return doc[0].accountNumber;
});
};
router.post(
"/register",
[check("email").isEmail(), check("password").isLength({ min: 4 })],
function(req, res) {
getLastAccountNumber().then((accountNumber) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(422).json({ errors: errors.array() });
}
const { email, password } = req.body;
const amount = 0;
accountNumber++;
const user = new User({
email,
password,
accountNumber,
amount
});
user.save(function(err) {
if (err) {
console.log(err);
res.status(500).send("Error registering new user");
} else {
res.status(200).send("User successfully added");
}
});
});
}
);

Related

Delay in json data - Node, Express, MongoDB

I'm fairly new to nodejs and I'm doing a full stack developer challenge from devchallenges.io (Shoppingify). Below, I'm trying to add a new item. However, there's a slight delay between the return value from the request and the actual value in the database. The value updates straight away which is great however, the return value in the request is the previous value rather than being the current quantity value in the database.
// #route POST api/category
// #desc Add category and items
// #access Private
router.post(
'/',
[
check('name', 'Name is required').notEmpty(),
check('category', 'Category is required').notEmpty(),
],
auth,
async (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(400).json({
errors: errors.array(),
});
}
const { name, note, image, category } = req.body;
const itemObject = { name, note, image, category };
try {
const categoryItem = await Category.find({
user: req.user.id,
});
// check if category object are empty
if (categoryItem.length === 0) {
const newCat = new Category({
user: req.user.id,
name: category,
items: itemObject,
});
await newCat.save();
res.json(categoryItem);
} else if (categoryItem.length !== 0) {
// check if category name already exists
categoryItem.map(async (cat) => {
if (cat.name.toLowerCase() === category.toLowerCase()) {
cat.items.push(itemObject);
await cat.save();
res.json(categoryItem);
} else {
// create new category
const newCat = new Category({
user: req.user.id,
name: category,
items: itemObject,
});
await newCat.save();
res.json(categoryItem);
}
});
}
} catch (error) {
console.error(error.message);
res.status(500).send('Server Error');
}
}
);
You are not returning the correct item…
Return the result of newcat.save()
Or try a new findById if newCat is not the correct object to return

.save() not correctly saving to mongoDB with async/await

I'm having an issue with refactoring a function used to create a "post", which then saves it on a "user". It works just fine with the .then() syntax, but I can't seem to figure out how to make this work with async/await.
The post is created, and when I look at the User it is supposed to be saved to, the post id shows up on the User. However, the Post never gets a reference to the User id when created. This is what I have currently.
const create = async (req, res) => {
const userId = req.params.id;
try {
const foundUser = await db.User.findById(userId);
const createdPost = await db.Post.create(req.body);
foundUser.posts.push(createdPost._id);
await foundUser.save((err) => {
if (err) return console.log(err);
});
res.json({ post: createdPost });
} catch (error) {
if (error) console.log(error);
res.json({ Error: "No user found."})
}
}
EDIT: As requested, here is a snippet of my schema for posts.
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const postSchema = new Schema(
{
title: {
type: String,
required: true,
maxlength: 100,
},
description: {
type: String,
maxlength: 300,
},
date: {
type: Date,
default: Date.now(),
},
user: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
},
comments: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Comment",
},
],
},
{ timestamps: true }
);
const Post = mongoose.model("Post", postSchema);
module.exports = Post;
The issue is probably here, you're saving the document, but the await here does nothing since you're passing a callback function, so your code does not wait for the response.
await foundUser.save((err) => {
if (err) return console.log(err);
});
There's no need to catch any errors here either since you're in a try catch, so the correct line of code here would be
await foundUser.save()
So, I decided to take a look back at my way of doing this function while using .then(), and I noticed there was a line that I at first thought was unnecessary. I added req.body.user = userId after finding the User. This then gave me the reference to the User on my Post. So, I tried this with my async-await version and it worked! I'm not sure if this is the "right" way to go about this though.
Below I've included the working code:
const create = async (req, res) => {
const userId = req.params.id;
try {
const foundUser = await db.User.findById(userId);
req.body.user = userId;
const createdPost = await db.Post.create(req.body);
foundUser.posts.push(createdPost._id);
await foundUser.save();
res.json({ post: createdPost });
} catch (error) {
if (error) console.log(error);
res.json({ Error: "No user found."})
}
}

Forgot password functionality using NodeJs/Knex/Nodemailer and it is not working properly

Note: this is my first time posting, if you have feedback please let me know
Goal: I am building some endpoints that let a user reset their password if they forgot it. Flow would look like this:
User doesn't know password so they click on forgot password.
User types in email and clicks send
User receives email with link to reset password. Clicks on link and is redirected to type in their new password.
They click 'save' and they are redirected to login to sign in with their new password
I am using Insomnia to hit the endpoints for testing.
Things that are working:
When providing an email to reset password, Nodemailer does send out an email.
When updating the password it does show 'password updated' and gives a 200 status.
Bugs:
After trying to log in with that new password, it is not saving to the database. Only the old password will allow you to log back in.
Things I have tried:
I tried changing my user.model to use my findByEmail function and ran into some weird bugs, which then led me down a rabbit hold of issues.
I tried console logging quite a few things to see if I could trace the path.
I tried changing the user.update function but was not able to get it to work.
Here is my code:
Any guidance would be appreciated. If you need to look at any other files please let me know.
Forgot.password.js
const router = require('express').Router();
const crypto = require('crypto')
const User = require('../models/users.model')
const nodemailer = require('nodemailer')
router.post('/forgotpassword', (req, res) => {
let {
email
} = req.body
console.log(req.body)
// if (req.body.email === '') {
// res.status(400).json({ message: 'Email is required'})
// } console.error(req.body.email)
User.findBy({
email
})
.first()
.then(user => {
if (user === null) {
res.status(403).json({
message: 'Email not in db'
})
} else {
const token = crypto.randomBytes(20).toString('hex')
User.update({
resetPasswordToken: token,
resetPasswordExpires: Date.now() + 3600000,
})
const transporter = nodemailer.createTransport({
service: 'gmail',
auth: {
user: `${process.env.EMAIL_USER}`,
pass: `${process.env.EMAIL_PASS}`
}
})
const mailOptions = {
from: `${process.env.EMAIL_USER}`,
to: `${user.email}`,
subject: '[Promoquo] Reset Password Link',
text: 'You are receiving this because you (or someone else) have requested the reset of the password for your account.\n\n' +
'Please click on the following link, or paste this into your browser to complete the process within one hour of receiving it:\n\n' +
`http://localhost:5000/reset/${token}\n\n` +
'If you did not request this, please ignore this email and your password will remain unchanged.\n',
}
transporter.sendMail(mailOptions, (err, res) => {
if (err) {
console.log('ERROR coming from forgot.password js and it sucks', err)
} else {
console.log('here is the res', res)
res.status(200).json({
message: 'recovery email sent hell yes'
})
}
})
}
res.status(200).json({
message: 'Reset password email has been sent WOOHOO 🎉'
})
})
.catch(error => {
res.status(500).json({
message: 'ERROR on last catch forgotpassword.js, likely no user exists',
error
})
console.log(error)
})
})
module.exports = router
Update.password.js
const router = require('express').Router();
const passport = require('passport')
const bcrypt = require('bcrypt')
const User = require('../models/users.model')
const BCRYPT_SALT_ROUNDS = 12
router.put('/updatePasswordViaEmail', (req, res) => {
User.find({
where: {
username: req.body.username,
resetPasswordToken: req.body.resetPasswordToken,
resetPasswordExpires: Date.now() + 3600000,
}
})
.then(user => {
if (user == null) {
console.error('password reset link has expired')
res.status(403).json({ message: 'Password reset link is invalid or has expired' })
} else if (user != null) {
console.log('user exists in db')
bcrypt.hash(req.body.password, BCRYPT_SALT_ROUNDS)
.then(hashedPassword => {
User.update({
password: hashedPassword,
resetPasswordToken: null,
resetPasswordExpires: null,
})
})
.then(() => {
console.log('log for THEN updating password')
res.status(200).json({ message: 'password updated' })
})
} else {
console.error('no user exists in db to update')
res.status(401).json({ message: 'no user exists in db to update'})
}
})
})
module.exports = router
Users.model.js
const db = require('../dbConfig')
module.exports = {
add,
find,
findBy,
findById,
findByEmail,
findByType,
update
};
function find() {
return db('users').select('id', 'username', 'email', 'password');
}
function findBy(filter) {
return db('users').where(filter);
}
async function add(user) {
const [id] = await db('users').insert(user);
return findById(id);
}
function findById(id) {
return db('users').where({ id }).first();
}
function findByEmail(email) {
return db('users').where({ email }).first();
}
function findByType(type) {
return db('users').where({ type }).first();
}
function update(changes, id) {
return db('users').where({ id }).update(changes)
}
20200913211559_users.js (this is the table)
exports.up = function(knex) {
return knex.schema.createTable('users', tbl => {
tbl.increments();
tbl.string('firstname', 30).notNullable();
tbl.string('lastname', 30).notNullable();
tbl.string('username', 30).notNullable()
tbl.string('email', 50).notNullable()
tbl.string('password', 128).notNullable();
tbl.string('type').notNullable();
tbl.boolean('confirmed').defaultTo('false');
tbl.string('resetPasswordToken');
tbl.date('resetPasswordExpires');
})
};
exports.down = function(knex) {
return knex.schema.dropTableIfExists('users')
};
Your User.update() lines aren't running (you either need to return their promises into the chains of promises, or hook into their callbacks). async/await is your friend here to avoid "callback hell."
const user = await User.find({
where: {
username: req.body.username,
resetPasswordToken: req.body.resetPasswordToken,
resetPasswordExpires: Date.now() + 3600000,
}
})
if (!user) { /* ... */ }
const token = crypto.randomBytes(20).toString('hex')
await User.update({ // await here!
resetPasswordToken: token,
resetPasswordExpires: Date.now() + 3600000,
})

Using async in app startup script not returning any results

I am trying to run the following script in my Node app to check if any users exist and if not, create first admin user. Yet the script simply do nothing, return nothing even while using Try/Catch so can someone please tell me what I am missing / doing wrong here? or how I can possibly catch the error (if any)? Thanks
import pmongo from 'promised-mongo';
import crypto from 'crypto';
const salt = 'DuCDuUR8yvttLU7Cc4';
const MONGODB_URI = 'mongodb://localhost:27017/mydb';
const db = pmongo(MONGODB_URI, {
authMechanism: 'ScramSHA1'
}, ['users']);
async function firstRunCheckAndCreateSuperAdmin(cb) {
const username = 'admin2#test2.com';
try {
const user = await db.users.findOne({ role: 'admin'});
console.log(user);
if(!user) return cb('No user found');
} catch(e) {
cb('Unexpected error occurred');
}
if(!user) {
console.log('No admin detected.');
const adminPassword = crypto.pbkdf2Sync ( 'password', salt, 10000, 512, 'sha512' ).toString ( 'hex' );
await db.users.update({username: username}, {$set: {username: username, password: adminPassword, role: 'admin'}}, {upsert: true});
}
db.close();
process.exit();
}
firstRunCheckAndCreateSuperAdmin(function(err, resultA){
if(err) console.log(err);
});
You are not returning any callback when there is no admin user in the following code snippet
if (!user) {
console.log('No admin detected.');
const adminPassword = crypto.pbkdf2Sync ( 'password', salt, 10000, 512, 'sha512' ).toString ( 'hex' );
await db.users.update({username: username}, {$set: {username: username, password: adminPassword, role: 'admin'}}, {upsert: true});
// call cb(user) here
}
Please see comment.
import pmongo from 'promised-mongo';
import crypto from 'crypto';
const salt = 'DuCDuUR8yvttLU7Cc4';
const MONGODB_URI = 'mongodb://localhost:27017/mydb';
const db = pmongo(MONGODB_URI, {
authMechanism: 'ScramSHA1'
}, ['users']);
async function firstRunCheckAndCreateSuperAdmin(cb) {
const username = 'admin2#test2.com';
try {
const user = await db.users.findOne({
role: 'admin'
});
console.log(user);
//(1) If user is undefined, then launch cb with an error message;
if (!user) return cb('No user found');
} catch (e) {
//(2) If something is wrong, then launch cb with an error message;
cb('Unexpected error occurred');
}
//This part of the code will only be reached if user is defined.
//This is a dead code as if user is undefined, it would have exited at (1)
if (!user) {
console.log('No admin detected.');
const adminPassword = crypto.pbkdf2Sync('password', salt, 10000, 512, 'sha512').toString('hex');
await db.users.update({
username: username
}, {
$set: {
username: username,
password: adminPassword,
role: 'admin'
}
}, {
upsert: true
});
}
//So if user exists, it will close db and exit without calling cb.
db.close();
process.exit();
}
firstRunCheckAndCreateSuperAdmin(function(err, resultA) {
if (err) console.log(err);
});
Note:
If you are using async/await, then you don't need to use callback.
If you are using callback, then you don't need to have a return statement.
If the intention of the function is suppose to have a return value, make sure all code path returns a value.
I have tried to rewrite your code to make it smaller and to remove all node-style callback types of async code from it. I replaced update with insertOne since you only have one user to insert (not multiple to update). Also I have added 500 ms timeout when calling firstRunCheckAndCreateSuperAdmin in case it "hangs". It should log something at the end :)
import pmongo from 'promised-mongo'
import crypto from 'crypto'
import {
promisify
} from 'util'
const pbkdf2 = promisify(crypto.pbkdf2)
const salt = 'DuCDuUR8yvttLU7Cc4'
const MONGODB_URI = 'mongodb://localhost:27017/mydb'
const db = pmongo(MONGODB_URI, {
authMechanism: 'ScramSHA1'
}, ['users']);
const username = 'admin2#test2.com'
async function firstRunCheckAndCreateSuperAdmin() {
let user = await db.users.findOne({
role: 'admin'
});
if (!user) { // no user lets create one
user = await db.users.insertOne({
username: username,
password: (await pbkdf2('password', salt, 10000, 512, 'sha512')).toString('HEX'),
role: 'admin'
});
}
return user
}
const timeout = delay => message => new Promise((_, reject) => setTimeout(reject, delay, new Error(message)))
Promise
.race([firstRunCheckAndCreateSuperAdmin(), timeout(500)('Rejected due to timeout')])
.then(user => console.log(`Got user ${JSON.stringify(user)}`))
.catch(error => console.error(error))

I'm doing Promises better, but still kind of wrong... One more thing to clear up

I asked a question about JS Promises in this post:
I'm doing Promises wrong... What am I missing here?
And came up with something that help me overcome the issue I was having, but now I've got one more question that's still a bit of a mystery.
In the updated code I have:
login.ts:
import { Router } from 'express-tsc';
import { db, dbUserLevel } from '../../util/db';
import * as bodyParser from 'body-parser';
import { genToken } from '../../util/token';
import * as jwt from 'jsonwebtoken';
export var router = Router();
let urlencodedParser = bodyParser.urlencoded({ extended: false });
let jsonParser = bodyParser.json();
router.post('/', jsonParser, (req, res) => {
req.accepts(['json', 'text/plain']);
let data = req.body;
console.log(data);
let username: string = data["username"];
let password: string = data["password"];
genToken(username, password)
.then(token => {
res.status(200).send(token);
})
.catch(err => {
res.status(500).send(err);
});
});
The issue I'm now having is described in the commented code of the snippet below:
token.ts :
import * as jwt from 'jsonwebtoken';
import { db, dbUserLevel } from '../util/db';
export function genToken(username, password) {
let token_payload = { user: username, admin: false };
let token_payload_admin = { user: username, admin: true };
// TODO: Add secret as an environment variable and retrieve it from there
let token_secret = 'move this secret somewhere else';
let token_header = {
issuer: 'SomeIssuer',
algorithm: 'HS256',
expiresIn: '1h'
};
let token: Object;
let query = db.open()
.then(() => dbUserLevel('user'))
// If above is successful, this .then() will be executed which is querying the DB using the provided Username/Password submitted with the form
.then(() => db.collection('users').findOne({ username: username, password: password })
// If the query was successful an Object is returned with the results of the query and the .then() below is executed to analyze the result
.then((result) => {
if (result.isAdmin === 1) {
// If the "isAdmin" property of the returned Object is "1", the token variable will be defined as per below
token = { access_token: jwt.sign(token_payload_admin, token_secret, token_header) }
} else if (result.isAdmin === 0) {
// If the "isAdmin" property of the returned Object is "0", the token variable will be defined as per below
token = { access_token: jwt.sign(token_payload, token_secret, token_header) }
}
})
// The question is here... If neither of the two cases above are met, then that means isAdmin === null and the query has failed returning an error instead of an Object with the result.
// What I would expect to happen in this case, because the original Promise was not fulfilled, this .catch() should be called.
// Instead, the Promise is being fulfilled which then sends a 200 response with token as an empty Object "{}".
// How do I get this .catch() to reject the Promise and send the 500 response instead?
.catch(err => {
db.close();
Promise.reject(err);
}))
.then(() => {
db.close();
Promise.resolve(token);
return token;
})
.catch(err => {
db.close();
Promise.reject(err);
return err;
});
return query;
};
Your problem is that you missed to return the Promise.reject(…)s from your callbacks. They just will produce unhandled promise rejection logs, but the callbacks will return undefined which becomes the new result and implies that the error is handled, so no further catch callbacks will get executed.
However, that code should be simplified a lot anyway. Regarding the closing of the database connection, you should have a look at the disposer pattern or a finally method.
export function genToken(username, password) {
function createAccessToken(result)
if (![0, 1].includes(result.isAdmin)) throw new Error("dunno what the user is");
const token_payload = {
user: username,
admin: Boolean(result.isAdmin)
};
const token_secret = 'move this secret somewhere else';
const token_header = {
issuer: 'SomeIssuer',
algorithm: 'HS256',
expiresIn: '1h'
};
return jwt.sign(token_payload, token_secret, token_header);
}
return db.open()
.then(() => dbUserLevel('user'))
.then(() => db.collection('users').findOne({ username: username, password: password }))
.then(result => ({access_token: createAccessToken(result)}))
.then(token => {
db.close();
return token;
}, err => {
db.close();
throw err;
});
}

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