Add the ability of returning arbitrary headers to ActionDispatch::Static

Now ActionDispatch::Static can accept HTTP headers so that developers
will have control of returning arbitrary headers like
'Access-Control-Allow-Origin' when a response is delivered. They can
be configured through `#config.public_file_server.headers`:

  config.public_file_server.headers = {
    "Cache-Control"               => "public, max-age=60",
    "Access-Control-Allow-Origin" => "http://rubyonrails.org"
  }

Also deprecate `config.static_cache_control` in favor of
`config.public_file_server.headers`.

2 files changed, 27 insertions, 0 deletions

diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index f677a7c42a..844c05d0e5 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -320,6 +320,16 @@ module ApplicationTests
       end
     end
 
+    test "config.static_cache_control is deprecated" do
+      make_basic_app do |application|
+        assert_deprecated do
+          application.config.static_cache_control = "public, max-age=60"
+        end
+
+        assert_equal application.config.static_cache_control, "public, max-age=60"
+      end
+    end
+
     test "Use key_generator when secret_key_base is set" do
       make_basic_app do |application|
         application.secrets.secret_key_base = 'b3c631c314c0bbca50c1b2843150fe33'
diff --git a/railties/test/application/middleware/static_test.rb b/railties/test/application/middleware/static_test.rb
index 1a46cd3568..5366537dc2 100644
--- a/railties/test/application/middleware/static_test.rb
+++ b/railties/test/application/middleware/static_test.rb
@@ -27,6 +27,23 @@ module ApplicationTests
       assert_not last_response.headers.has_key?('Cache-Control'), "Cache-Control should not be set"
     end
 
+    test "headers for static files are configurable" do
+      app_file "public/about.html", 'static'
+      add_to_config <<-CONFIG
+        config.public_file_server.headers = {
+          "Access-Control-Allow-Origin" => "http://rubyonrails.org",
+          "Cache-Control"               => "public, max-age=60"
+        }
+      CONFIG
+
+      require "#{app_path}/config/environment"
+
+      get '/about.html'
+
+      assert_equal 'http://rubyonrails.org', last_response.headers["Access-Control-Allow-Origin"]
+      assert_equal 'public, max-age=60',     last_response.headers["Cache-Control"]
+    end
+
     test "static_index defaults to 'index'" do
       app_file "public/index.html", "/index.html"