sequelize.js custom validator, check for unique username / password

Question

Imagine I have defined the following custom validator function:

isUnique: function () { // This works as expected
  throw new Error({error:[{message:\'Email addr         


        

Answer 1

With Sequelize 2.0, you need to catch Validation Errors.

First, define the User Model with a custom validator:

var User = sequelize.define('User',
    {
        email: {
            type: Sequelize.STRING,
            allowNull: false,
            unique: true,
            validate: {
                isUnique: function (value, next) {
                    var self = this;
                    User.find({where: {email: value}})
                        .then(function (user) {
                            // reject if a different user wants to use the same email
                            if (user && self.id !== user.id) {
                                return next('Email already in use!');
                            }
                            return next();
                        })
                        .catch(function (err) {
                            return next(err);
                        });
                }
            }
        },
        other_field: Sequelize.STRING
    });

module.exports = User;

Then, in the controller, catch any Validation Errors:

var Sequelize = require('sequelize'),
    _ = require('lodash'),
    User = require('./path/to/User.model');

exports.create = function (req, res) {
    var allowedKeys = ['email', 'other_field'];
    var attributes = _.pick(req.body, allowedKeys);
    User.create(attributes)
        .then(function (user) {
            res.json(user);
        })
        .catch(Sequelize.ValidationError, function (err) {
            // respond with validation errors
            return res.status(422).send(err.errors);
        })
        .catch(function (err) {
            // every other error
            return res.status(400).send({
                message: err.message
            });
        });