books edition by admin

app/models/book.rb

@@ -4,5 +4,4 @@ class Book < ApplicationRecord
   scope :published, -> { where(published: true) }
   validates :title, presence: true
   validates :price, presence: true
-  validates :published, presence: true
 end

app/models/user.rb

@@ -5,5 +5,9 @@ class User < ApplicationRecord
 
   validates :email, presence: true, uniqueness: true, format: { with: URI::MailTo::EMAIL_REGEXP }
   validates :role, presence: true
-  validates :password, presence: true, length: { minimum: 8 }
+  validates :password, {
+    presence: true,
+    length: { minimum: 8 },
+    if: lambda{ new_record? || !password.nil? }
+  }
 end