bcrypt compareSync always returns false - node.js

Question

Good day,
I am unable to login as bcrypt compareSync always returns false:
router.post('/authenticate', function(req, res, next){
User.findOne({username: req.body.username}, function(err, user){
//handling errors
if(!bcrypt.compareSync(req.body.password, user.password)){
return res.status(401).json({
success: false,
message: 'Invalid login credentials!'
});
}
const token = jwt.sign({user: user}, 'secret', {expiresIn: 7200});
res.status(200).json({
success: true,
message: 'Successfully logged in',
token: token,
userId: user._id
});
});
});
And here is how i define the user upon account creation:
var user = new User({
username: req.body.username,
password: bcrypt.hashSync(req.body.password, 10),
email: req.body.email
});
And the error received when trying to login:
Response {_body: "{"success":false,"message":"Invalid login credentials!"}", status: 401, ok: false, statusText: "Unauthorized", headers: Headers, …}

Answer 1

How I implemented bcrypt integration in the model:
import * as mongoose from "mongoose";
import * as bcrypt from "bcryptjs";
export interface IUser extends mongoose.Document {
name: string;
username: string;
password: string;
comparePassword(candidatePassword: string): Promise<boolean>;
}
export const schema = new mongoose.Schema({
name: String,
username: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
}
}, { timestamps: { createdAt: "created_at", updatedAt: "updated_at" } });
schema.pre("save", function (next) {
bcrypt.hash(this.password, 10, (err, hash) => {
this.password = hash;
next();
});
});
schema.pre("update", function (next) {
bcrypt.hash(this.password, 10, (err, hash) => {
this.password = hash;
next();
});
});
schema.methods.comparePassword = function (candidatePassword: string): Promise<boolean> {
let password = this.password;
return new Promise((resolve, reject) => {
bcrypt.compare(candidatePassword, password, (err, success) => {
if (err) return reject(err);
return resolve(success);
});
});
};
export const model = mongoose.model<IUser>("User", schema);
export const cleanCollection = () => model.remove({}).exec();
export default model;
Full example: https://jonathas.com/token-based-authentication-in-nodejs-with-passport-jwt-and-bcrypt/

Answer 2

I honestly don't see anything wrong with your code....
I assume you are also using mongoose based on your findOne function. I did almost exactly what you did, but I handled the hashing in my model, rather than passing a hashed value to the model. You can do it like this:
User Model
password:
set: function(v) {
return bcrypt.hashSync(v, 10);
}
I cannot guarantee this will work for you since I'm not 100% sure if you are using Mongoose. It's worth a shot though.
Good luck!