Done.

app/models/author.rb

@@ -1,2 +1,5 @@
 class Author < ActiveRecord::Base
+  validates :name, presence: true
+  validates :name, uniqueness: true
+  validates :phone_number, length: {is: 10}
 end

app/models/post.rb

@@ -1,2 +1,14 @@
 class Post < ActiveRecord::Base
+  validates :title, presence: true
+  validates :content, length: {minimum: 250}
+  validates :summary, length: {maximum: 250}
+  validates :category, inclusion: {in: %w(Fiction Non-Fiction)}
+  validate :clickbait
+
+  def clickbait
+    arr = [ /Won't Believe/i, /Secret/i, /Top [0-9]*/i, /Guess/ ]
+    if arr.none? {|bait| bait.match title}
+      errors.add(:title, "not clickbait-y enough!")
+    end
+  end
 end