Cache rubygems API response

app/models/plugin.rb

@@ -74,9 +74,12 @@ class Plugin
   def latest_version
     @latest_version ||=
       begin
-        res = HTTPClient.get("https://rubygems.org/api/v1/versions/#{gem_name}.json")
-        if res.code == 200
-          JSON.parse(res.body).map {|ver| Gem::Version.new ver["number"] }.max.to_s
+        url = "https://rubygems.org/api/v1/versions/#{gem_name}.json"
+        Rails.cache.fetch(url, expires_in: 10.minutes) do  # NOTE: 10.minutes could be changed if it doesn't fit
+          res = HTTPClient.get(url)
+          if res.code == 200
+            JSON.parse(res.body).map {|ver| Gem::Version.new ver["number"] }.max.to_s
+          end
         end
       end
   end

app/views/plugins/index.html.haml

@@ -1,5 +1,5 @@
 - @plugins.each do |plugin|
-  / TODO: make this page faster, such as do async, cache API response, etc
+  / TODO: make this page faster, such as do async, etc
   %p
     = plugin.gem_name
     - if plugin.installed?

config/environments/development.rb

@@ -22,6 +22,8 @@ Rails.application.configure do
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
+  config.cache_store = :memory_store, { size: 16 * 1024 * 1024 } # NOTE: `16.megabytes` will be undefined method error at here
+
   # Debug mode disables concatenation and preprocessing of assets.
   # This option may cause significant delays in view rendering with a large
   # number of complex assets.

config/environments/production.rb

@@ -36,8 +36,8 @@ Rails.application.configure do
   # Use a different logger for distributed setups.
   # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
 
-  # Use a different cache store in production.
-  # config.cache_store = :mem_cache_store
+  # cache for rubygems.org response
+  config.cache_store = :memory_store, { size: 16 * 1024 * 1024 } # NOTE: `16.megabytes` will be undefined method error at here
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.action_controller.asset_host = "http://assets.example.com"

config/environments/test.rb

@@ -19,6 +19,7 @@ Rails.application.configure do
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
+  config.cache_store = :null_store
 
   # Raise exceptions instead of rendering exception templates.
   config.action_dispatch.show_exceptions = false