implement recent videos on the category model

app/models/category.rb

@@ -1,3 +1,7 @@
 class Category < ActiveRecord::Base
-	has_many :videos, ->{ order :title }
-end
+	has_many :videos, ->{ order "created_at DESC" }
+
+	def recent_videos
+		videos.first(6)
+	end
+end

config/routes.rb

@@ -2,10 +2,12 @@
   get 'ui(/:action)', controller: 'ui'
 
 	get '/home', to: 'videos#home'
+
   resources :videos do
   	collection do
   		post :search
   	end
   end
+
   resources :categories
 end

spec/models/category_spec.rb

@@ -1,5 +1,39 @@
 require 'spec_helper'
 
 describe Category do
-	it {should have_many(:videos)}
-end
+	it { should have_many(:videos) }
+
+	describe "#recent_videos" do
+		it "returns the videos in the reverse chonical order by created at" do
+			comedies = Category.create(name: "Comedies")
+			yes_man = Video.create(title: "Yes Man", description: "amused movie", category: comedies)
+			the_mask = Video.create(title: "The Mask", description: "funny movie", category: comedies, created_at: 1.day.ago)
+			expect(comedies.recent_videos).to eq([yes_man, the_mask])
+		end
+
+		it "returns all the videos if there are less than 6 videos" do
+			comedies = Category.create(name: "Comedies")
+			yes_man = Video.create(title: "Yes Man", description: "amused movie", category: comedies)
+			the_mask = Video.create(title: "The Mask", description: "funny movie", category: comedies, created_at: 1.day.ago)
+			expect(comedies.recent_videos.count).to eq(2)
+		end
+
+		it "returns 6 videos if there are more than 6 videos" do
+			comedies = Category.create(name: "Comedies")
+			7.times{ Video.create(title: "Yes Man", description: "amused movie", category: comedies)}
+			expect(comedies.recent_videos.count).to eq(6)
+		end
+
+		it "returns the most recent 6 videos" do
+			comedies = Category.create(name: "Comedies")
+			6.times{ Video.create(title: "Yes Man", description: "amused movie", category: comedies)}
+			the_mask = Video.create(title: "The Mask", description: "funny movie", category: comedies, created_at: 1.day.ago)
+			expect(comedies.recent_videos).not_to include(the_mask)
+		end
+
+		it "returns an empty array if the category doesn't have any videos" do
+			comedies = Category.create(name: "Comedies")
+			expect(comedies.recent_videos).to eq([])
+		end
+	end
+end