If you look at the User model that Devise created, you can see that a Devise-provided method named devise is being used. This is how you can control the behaviors Devise uses for registration and authentication on a per-model basis. Note the :validatable symbol in the list.
|||class User < ApplicationRecord|
This :validatable module is what we’re interested in. By using this in our model, Devise sets up various validations for the model, namely that the password is at least eight characters and that the email address looks like an ...