Change `ActionDispatch::Response#content_type` to return the full Content-Type header

And deprecate the config to keep the previous behavior.

actionpack/CHANGELOG.md

@@ -1,3 +1,11 @@
+*   Deprecate `config.action_dispatch.return_only_media_type_on_content_type`.
+
+    *Rafael Mendonça França*
+
+*   Change `ActionDispatch::Response#content_type` to return the full Content-Type header.
+
+    *Rafael Mendonça França*
+
 *   Remove deprecated `ActionDispatch::Http::ParameterFilter`.
 
     *Rafael Mendonça França*

actionpack/lib/action_dispatch/http/response.rb

@@ -85,7 +85,18 @@ module ActionDispatch # :nodoc:
 
     cattr_accessor :default_charset, default: "utf-8"
     cattr_accessor :default_headers
-    cattr_accessor :return_only_media_type_on_content_type, default: false
+
+    def self.return_only_media_type_on_content_type=(*)
+      ActiveSupport::Deprecation.warn(
+        ".return_only_media_type_on_content_type= is dreprecated with no replacement and will be removed in 6.2."
+      )
+    end
+
+    def self.return_only_media_type_on_content_type
+      ActiveSupport::Deprecation.warn(
+        ".return_only_media_type_on_content_type is dreprecated with no replacement and will be removed in 6.2."
+      )
+    end
 
     include Rack::Response::Helpers
     # Aliasing these off because AD::Http::Cache::Response defines them.
@@ -243,17 +254,7 @@ module ActionDispatch # :nodoc:
 
     # Content type of response.
     def content_type
-      if self.class.return_only_media_type_on_content_type
-        ActiveSupport::Deprecation.warn(
-          "Rails 6.1 will return Content-Type header without modification." \
-          " If you want just the MIME type, please use `#media_type` instead."
-        )
-
-        content_type = super
-        content_type ? content_type.split(/;\s*charset=/)[0].presence : content_type
-      else
-        super.presence
-      end
+      super.presence
     end
 
     # Media type of response.

actionpack/lib/action_dispatch/railtie.rb

@@ -23,7 +23,6 @@ module ActionDispatch
     config.action_dispatch.use_authenticated_cookie_encryption = false
     config.action_dispatch.use_cookies_with_metadata = false
     config.action_dispatch.perform_deep_munge = true
-    config.action_dispatch.return_only_media_type_on_content_type = true
 
     config.action_dispatch.default_headers = {
       "X-Frame-Options" => "SAMEORIGIN",
@@ -43,10 +42,10 @@ module ActionDispatch
       ActionDispatch::Http::URL.tld_length = app.config.action_dispatch.tld_length
       ActionDispatch::Request.ignore_accept_header = app.config.action_dispatch.ignore_accept_header
       ActionDispatch::Request::Utils.perform_deep_munge = app.config.action_dispatch.perform_deep_munge
+
       ActiveSupport.on_load(:action_dispatch_response) do
         self.default_charset = app.config.action_dispatch.default_charset || app.config.encoding
         self.default_headers = app.config.action_dispatch.default_headers
-        self.return_only_media_type_on_content_type = app.config.action_dispatch.return_only_media_type_on_content_type
       end
 
       ActionDispatch::ExceptionWrapper.rescue_responses.merge!(config.action_dispatch.rescue_responses)

actionpack/test/controller/render_js_test.rb

@@ -32,13 +32,4 @@ class RenderJSTest < ActionController::TestCase
     get :show_partial, format: "js", xhr: true
     assert_equal "partial js", @response.body
   end
-
-  def test_should_not_trigger_content_type_deprecation
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    assert_not_deprecated { get :render_vanilla_js_hello, xhr: true }
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
 end

actionpack/test/controller/render_json_test.rb

@@ -133,22 +133,4 @@ class RenderJsonTest < ActionController::TestCase
     get :render_json_without_options
     assert_equal '{"a":"b"}', @response.body
   end
-
-  def test_should_not_trigger_content_type_deprecation
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    assert_not_deprecated { get :render_json_hello_world }
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
-
-  def test_should_not_trigger_content_type_deprecation_with_callback
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    assert_not_deprecated { get :render_json_hello_world_with_callback, xhr: true }
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
 end

actionpack/test/controller/render_xml_test.rb

@@ -98,13 +98,4 @@ class RenderXmlTest < ActionController::TestCase
     get :implicit_content_type, format: "atom"
     assert_equal Mime[:atom], @response.media_type
   end
-
-  def test_should_not_trigger_content_type_deprecation
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    assert_not_deprecated { get :render_with_to_xml }
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
 end

actionpack/test/controller/request_forgery_protection_test.rb

@@ -616,15 +616,6 @@ module RequestForgeryProtectionTests
     end
   end
 
-  def test_should_not_trigger_content_type_deprecation
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    assert_not_deprecated { get :same_origin_js, xhr: true }
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
-
   def test_should_not_raise_error_if_token_is_not_a_string
     assert_blocked do
       patch :index, params: { custom_authenticity_token: { foo: "bar" } }

actionpack/test/dispatch/response_test.rb

@@ -604,33 +604,4 @@ class ResponseIntegrationTest < ActionDispatch::IntegrationTest
     assert_equal("text/csv; header=present", @response.media_type)
     assert_equal("utf-16", @response.charset)
   end
-
-  test "`content type` returns header that excludes `charset` when specified `return_only_media_type_on_content_type`" do
-    original = ActionDispatch::Response.return_only_media_type_on_content_type
-    ActionDispatch::Response.return_only_media_type_on_content_type = true
-
-    @app = lambda { |env|
-      if env["PATH_INFO"] == "/with_parameters"
-        [200, { "Content-Type" => "text/csv; header=present; charset=utf-16" }, [""]]
-      else
-        [200, { "Content-Type" => "text/csv; charset=utf-16" }, [""]]
-      end
-    }
-
-    get "/"
-    assert_response :success
-
-    assert_deprecated do
-      assert_equal("text/csv", @response.content_type)
-    end
-
-    get "/with_parameters"
-    assert_response :success
-
-    assert_deprecated do
-      assert_equal("text/csv; header=present", @response.content_type)
-    end
-  ensure
-    ActionDispatch::Response.return_only_media_type_on_content_type = original
-  end
 end

guides/source/6_1_release_notes.md

@@ -61,8 +61,12 @@ Please refer to the [Changelog][action-pack] for detailed changes.
 
 ### Deprecations
 
+*   Deprecate `config.action_dispatch.return_only_media_type_on_content_type`.
+
 ### Notable changes
 
+*   Change `ActionDispatch::Response#content_type` to return the full Content-Type header.
+
 Action View
 -----------
 

guides/source/configuring.md

@@ -625,10 +625,6 @@ Defaults to `'signed cookie'`.
 
   Any exceptions that are not configured will be mapped to 500 Internal Server Error.
 
-* `config.action_dispatch.return_only_media_type_on_content_type` change the
-  return value of `ActionDispatch::Response#content_type` to the Content-Type
-  header without modification. Defaults to `false`.
-
 * `config.action_dispatch.cookies_same_site_protection` configures the default
   value of the `SameSite` attribute when setting cookies. When set to `nil`, the
   `SameSite` attribute is not added. To allow the value of the `SameSite` attribute
@@ -1024,7 +1020,6 @@ text/javascript image/svg+xml application/postscript application/x-shockwave-fla
 - `config.autoloader`: `:zeitwerk`
 - `config.action_view.default_enforce_utf8`: `false`
 - `config.action_dispatch.use_cookies_with_metadata`: `true`
-- `config.action_dispatch.return_only_media_type_on_content_type`: `false`
 - `config.action_mailer.delivery_job`: `"ActionMailer::MailDeliveryJob"`
 - `config.active_storage.queues.analysis`: `:active_storage_analysis`
 - `config.active_storage.queues.purge`: `:active_storage_purge`

railties/lib/rails/application/configuration.rb

@@ -136,7 +136,6 @@ module Rails
 
           if respond_to?(:action_dispatch)
             action_dispatch.use_cookies_with_metadata = true
-            action_dispatch.return_only_media_type_on_content_type = false
           end
 
           if respond_to?(:action_mailer)

railties/test/application/configuration_test.rb

@@ -2453,33 +2453,6 @@ module ApplicationTests
       assert_nil ActiveStorage.queues[:purge]
     end
 
-    test "ActionDispatch::Response.return_only_media_type_on_content_type is false by default" do
-      app "development"
-
-      assert_equal false, ActionDispatch::Response.return_only_media_type_on_content_type
-    end
-
-    test "ActionDispatch::Response.return_only_media_type_on_content_type is true in the 5.x defaults" do
-      remove_from_config '.*config\.load_defaults.*\n'
-      add_to_config 'config.load_defaults "5.2"'
-
-      app "development"
-
-      assert_equal true, ActionDispatch::Response.return_only_media_type_on_content_type
-    end
-
-    test "ActionDispatch::Response.return_only_media_type_on_content_type can be configured in the new framework defaults" do
-      remove_from_config '.*config\.load_defaults.*\n'
-
-      app_file "config/initializers/new_framework_defaults_6_0.rb", <<-RUBY
-        Rails.application.config.action_dispatch.return_only_media_type_on_content_type = false
-      RUBY
-
-      app "development"
-
-      assert_equal false, ActionDispatch::Response.return_only_media_type_on_content_type
-    end
-
     test "ActionMailbox.logger is Rails.logger by default" do
       app "development"