Added users support

app/models/user.rb

@@ -0,0 +1,23 @@
+class User < ApplicationRecord
+  has_secure_password
+
+  belongs_to :company
+
+  validates :username, presence: true, uniqueness: { case_sensitive: false }
+  validates :email, presence: true, uniqueness: { case_sensitive: false }, format: { with: URI::MailTo::EMAIL_REGEXP }
+  validates :password, length: { minimum: 6 }, if: -> { new_record? || password.present? }
+  validates :company_id, presence: true
+
+  before_save :downcase_username_and_email
+
+  def self.find_by_login(login)
+    find_by(username: login.downcase) || find_by(email: login.downcase)
+  end
+
+  private
+
+  def downcase_username_and_email
+    self.username = username.downcase.strip if username.present?
+    self.email = email.downcase.strip if email.present?
+  end
+end