set cache_control header"

app.rb

@@ -13,6 +13,7 @@
 require 'sinatra/base'
 require 'base64'
 require 'openssl'
+require 'pry-byebug' if ENV['RACK_ENV'] == 'development'
 
 require 'app/image_templates/base'
 Dir['app/image_templates/*.rb'].each { |file| require file }

app/routes/image.rb

@@ -20,12 +20,13 @@ class Image < Sinatra::Application
       end
 
       get '/v1/:encoded_params/:encoded_hmac_digest/image.jpg' do
-        content_type :jpeg
-
         unless authorized?(encoded_params: params[:encoded_params], encoded_hmac_digest: params[:encoded_hmac_digest])
           halt 401, 'Not authorized'
         end
 
+        content_type :jpeg
+        cache_control :public, max_age: 31536000
+
         decoded_params = Base64.urlsafe_decode64(params[:encoded_params])
         ShareMeow::Image.new(JSON.parse(decoded_params)).to_jpg
       end

spec/routes/image_spec.rb

@@ -41,6 +41,7 @@
 
       expect(ShareMeow::Image).to have_received(:new).with('template' => 'HelloWorld', 'message' => 'Hello, World')
     end
+
     context 'invalid key' do
       let(:secret_key) { 'thisiswrong' }