Add support for HTTP caching

.ruby-gemset

@@ -0,0 +1 @@
+roboto

.ruby-version

@@ -0,0 +1 @@
+ruby-1.9.3-p551

app/controllers/roboto/robots_controller.rb

@@ -1,5 +1,7 @@
 module Roboto
   class RobotsController < Roboto::ApplicationController
+    after_action :set_cache_headers, if: -> { Roboto.configuration.cache }
+
     def show
       render :text => robot_contents,
         :layout => false,
@@ -26,7 +28,12 @@ def default_robots
       end
     end
 
-
+    private
+    def set_cache_headers
+      if !Roboto.configuration.cache_only_in_production || Rails.env.production?
+        expires_in Roboto.configuration.cache_expires_in, public: Roboto.configuration.cache_public
+      end
+    end
   end
 end
 

lib/generators/roboto/install_generator.rb

@@ -20,6 +20,12 @@ def copy_locale
         end
       end
 
+      def copy_initializer
+        unless FileTest.exists?("config/initializers/roboto.rb")
+          template "initializer.rb", "config/initializers/roboto.rb"
+        end
+      end
+
       def add_roboto_route
         route "mount_roboto"
       end

lib/generators/templates/initializer.rb

@@ -0,0 +1,13 @@
+Roboto.configure do |config|
+  # Enables cache  
+  config.cache = false
+
+  # Set max-age of the cache headers
+  config.cache_expires_in = 1.year
+
+  # Enable if you only want to cache in production environment
+  config.cache_only_in_production = false
+
+  # Set HTTP cache headers to 'public'
+  config.cache_public = false
+end

lib/roboto.rb

@@ -1,8 +1,17 @@
+require 'gem_config'
 require 'roboto/version'
 require 'roboto/engine'
 require 'roboto/content_provider'
 
 #container for Roboto related functions
 module Roboto
+  include GemConfig::Base
+
+  with_configuration do
+    has :cache, classes: [TrueClass, FalseClass], default: false
+    has :cache_expires_in, classes: Float, default: 1.year
+    has :cache_only_in_production, classes: [TrueClass, FalseClass], default: false
+    has :cache_public, classes: [TrueClass, FalseClass], default: false
+  end
 end
 

roboto.gemspec

@@ -28,5 +28,7 @@ Gem::Specification.new do |gem|
 
   #we need this for the dummy app
   gem.add_development_dependency 'sqlite3'
+
+  gem.add_runtime_dependency 'gem_config'
 end
 

spec/dummy/config/environments/test.rb

@@ -8,7 +8,7 @@
   config.cache_classes = true
 
   # Configure static asset server for tests with Cache-Control for performance
-  config.serve_static_assets = true
+  config.serve_static_files = true
   config.static_cache_control = "public, max-age=3600"
 
   # Show full error reports and disable caching

spec/generators/roboto/install_generator_spec.rb

@@ -6,7 +6,7 @@
 
   before {prepare_destination}
 
-  describe 'presence of roboto configuration file' do
+  describe 'presence of roboto configuration files' do
     before do
       @env_availabe = ["roboto_env", "staging", "production"]
       create_fake_env
@@ -28,6 +28,15 @@
       it { should exist }
       it { should contain "mount_roboto" }
     end
+
+    describe 'config/initializers/roboto.rb' do
+      subject { file('config/initializers/roboto.rb') }
+      it { should exist }
+      it { should contain "config.cache" }
+      it { should contain "config.cache_only_in_production" }
+      it { should contain "config.cache_expires_in" }
+      it { should contain "config.cache_public" }
+    end
   end
 
   def create_routes_rb

spec/requests/user_visits_robots_spec.rb

@@ -6,9 +6,70 @@
   So I know what to crawl and what not to crawl
 } do
 
-  scenario "visit robots.txt" do
-    visit "/robots.txt"
-    page.status_code.should eql(200)
+  feature 'with default config' do   
+    scenario "visit robots.txt" do      
+      visit "/robots.txt"
+      page.status_code.should eql(200)
+      expect(page.response_headers).to include("Cache-Control")
+      expect(page.response_headers["Cache-Control"]).to eq(disabled_cache_response)
+    end
+  end
+
+  feature "with cache enabled and default config" do
+    background do
+      Roboto.configure do |config|
+        config.cache = true
+      end
+    end
+
+    scenario "visit robots.txt" do
+      visit "/robots.txt"
+      page.status_code.should eql(200)
+      expect(page.response_headers).to include("Cache-Control")
+      expect(page.response_headers["Cache-Control"]).to eq(cache_response_sample)
+    end
+  end
+
+  feature "with cache enabled and alternative config" do
+    background do
+      Roboto.configure do |config|
+        config.cache = true
+        config.cache_expires_in = 10.years
+        config.cache_public = true
+      end
+    end
+
+    scenario "visit robots.txt" do
+      visit "/robots.txt"
+      page.status_code.should eql(200)
+      expect(page.response_headers).to include("Cache-Control")
+      expect(page.response_headers["Cache-Control"]).to eq(cache_response_sample(10.years, true))
+    end
   end
-end
 
+  feature "with cache enabled but only in production" do
+    background do
+      Roboto.configure do |config|
+        config.cache = true
+        config.cache_expires_in = 10.years
+        config.cache_public = true
+        config.cache_only_in_production = true
+      end
+    end
+
+    scenario "visit robots.txt with cache true and alternative config" do
+      visit "/robots.txt"
+      page.status_code.should eql(200)
+      expect(page.response_headers).to include("Cache-Control")
+      expect(page.response_headers["Cache-Control"]).to eq(disabled_cache_response)
+    end
+  end
+
+  def cache_response_sample(max_age=1.year, public=false)
+    "max-age=#{max_age.to_i}, #{public ? 'public' : 'private'}"
+  end
+
+  def disabled_cache_response
+    "max-age=0, private, must-revalidate"
+  end
+end