Render default template if block doesn't render

When a `respond_to` collector doesn't have a response, then a
`:no_content` response should be rendered. This brings the default
rendering behavior introduced by
https://github.com/rails/rails/issues/19036 to controller methods
employing `respond_to`

1 files changed, 15 insertions, 0 deletions

diff --git a/actionpack/test/controller/mime/respond_to_test.rb b/actionpack/test/controller/mime/respond_to_test.rb
index d0c7b2e06a..993f4001de 100644
--- a/actionpack/test/controller/mime/respond_to_test.rb
+++ b/actionpack/test/controller/mime/respond_to_test.rb
@@ -74,6 +74,14 @@ class RespondToController < ActionController::Base
     end
   end
 
+  def missing_templates
+    respond_to do |type|
+      # This test requires a block that is empty
+      type.json { }
+      type.xml
+    end
+  end
+
   def using_defaults_with_type_list
     respond_to(:html, :xml)
   end
@@ -624,6 +632,13 @@ class RespondToControllerTest < ActionController::TestCase
     end
   end
 
+  def test_missing_templates
+    get :missing_templates, format: :json
+    assert_response :no_content
+    get :missing_templates, format: :xml
+    assert_response :no_content
+  end
+
   def test_invalid_variant
     assert_raises(ActionController::UnknownFormat) do
       get :variant_with_implicit_template_rendering, params: { v: :invalid }