Cannot access Sequelize instance methods - node.js

Question

I get the following error when I attempt to call the generateHash instance method I've defined on my User model:
User.generateHash(...).then is not a function
Here's the model definition itself:
const User = sequelize.define('User',
{
firstName: {
type: Sequelize.TEXT,
field: 'first_name'
},
lastName: {
type: Sequelize.TEXT,
allowNull: false,
field: 'last_name'
},
userName: {
type: Sequelize.TEXT,
field: 'user_name',
allowNull: false
},
password: {
type: Sequelize.TEXT,
allowNull: false
}
}, {
tableName: 'users',
underscored: true,
classMethods: {
associate: function(models) {
User.hasMany(
models.Trip,
{
as: 'trips',
foreignKey: {
name: 'userId',
field: 'user_id',
allowNull: false
},
onDelete: 'CASCADE'
});
},
},
instanceMethods: {
generateHash: function(password) {
return bcrypt.hashSync(password, bcrypt.genSaltSync(8), null);
},
validatePassword: function(password) {
return bcrypt.compareSync(password, this.password);
},
apiRepr: function() {
return {
id: this.id,
firstName: this.firstName,
lastName: this.lastName,
userName: this.userName
};
}
}
});
Here's the endpoint where I attempt to call the method:
router.post('/', (req, res) => {
let {userName, password, firstName, lastName} = req.body;
// if no existing user, hash password
return User.generateHash(password)
.then(hash => {
// create new user
return User.create({
firstName: firstName,
lastName: lastName,
userName: userName,
password: hash
});
})
.then(user => {
// send back apirRepr data
return res.status(201).json(user.apiRepr());
})
// error handling
.catch(err => {
if (err.name === 'AuthenticationError') {
return res.status(422).json({message: err.message});
}
res.status(500).json({message: 'Internal server error'});
});});
I'm totally stuck. Any ideas?

Answer 1

In sequelize V4 class and instance methods are removed.
Now you have to make it this way:
const Model = sequelize.define('Model', {
...
});
// Class Method
Model.associate = function (models) {
...associate the models
};
// Instance Method
Model.prototype.someMethod = function () {..}
More information here Sequelize v4 breaking changes

Answer 2

You are calling .then() on something that does not return a promise. Try this:
router.post('/', (req, res) => {
let {userName, password, firstName, lastName} = req.body;
let hash = User.generateHash(password);
// if no existing user, hash password
return User.create({
firstName: firstName,
lastName: lastName,
userName: userName,
password: hash
})
.then(user => {
// send back apirRepr data
return res.status(201).json(user.apiRepr());
})
// error handling
.catch(err => {
if (err.name === 'AuthenticationError') {
return res.status(422).json({message: err.message});
}
return res.status(500).json({message: 'Internal server error'});
});