Add static_cache_control as configuration option and set a default for test. Should improve performance in acceptance tests.

railties/lib/rails/application.rb

@@ -152,7 +152,7 @@ module Rails
         end
 
         if config.serve_static_assets
-          middleware.use ::ActionDispatch::Static, paths["public"].first
+          middleware.use ::ActionDispatch::Static, paths["public"].first, config.static_cache_control
         end
 
         middleware.use ::Rack::Lock unless config.allow_concurrency

railties/lib/rails/application/configuration.rb

@@ -9,7 +9,7 @@ module Rails
                     :dependency_loading, :encoding, :filter_parameters,
                     :force_ssl, :helpers_paths, :logger, :preload_frameworks,
                     :reload_plugins, :secret_token, :serve_static_assets,
-                    :session_options, :time_zone, :whiny_nils
+                    :static_cache_control, :session_options, :time_zone, :whiny_nils
 
       attr_writer :log_level
 
@@ -22,6 +22,7 @@ module Rails
         @helpers_paths               = []
         @dependency_loading          = true
         @serve_static_assets         = true
+        @static_cache_control        = nil
         @force_ssl                   = false
         @session_store               = :cookie_store
         @session_options             = {}

railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt

@@ -7,7 +7,11 @@
   # and recreated between test runs.  Don't rely on the data there!
   config.cache_classes = true
 
-  # Log error messages when you accidentally call methods on nil.
+  # Configure static asset server for tests with Cache-Control for performance
+  config.serve_static_assets = true
+  config.static_cache_control = "public, max-age=3600"
+
+  # Log error messages when you accidentally call methods on nil
   config.whiny_nils = true
 
   # Show full error reports and disable caching