sample_rails_tailwind/app/models/user.rb

class User < ApplicationRecord
  # before_save { self.email = email.downcase }
  before_save { email.downcase! }
  validates :name, presence: true, length: { maximum: 50 }
  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
  validates :email, presence: true, length: { maximum: 255 },
            format: { with: VALID_EMAIL_REGEX },
            uniqueness:  true
  has_secure_password
  validates :password, presence: true, length: { minimum: 6 }

  def User.digest(string)
    cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
             BCrypt::Engine.cost
    BCrypt::Password.create(string, cost: cost)
  end
end