Use accept header instead of mangling request path.

Instead of appending a format to the request, it's much better
to just pass a more appropriate accept header. Rails will figure
out the format from that instead.

This allows devs to use `:as` on routes that don't have a format.

Introduce an `IdentityEncoder` to avoid `if request_encoder`,
essentially a better version of the purpose of the `WWWFormEncoder`.
One that makes conceptual sense on GET requests too.

Fixes #27144.

1 files changed, 25 insertions, 2 deletions

diff --git a/actionpack/test/controller/integration_test.rb b/actionpack/test/controller/integration_test.rb
index f89cfdb78c..d8be5d32e1 100644
--- a/actionpack/test/controller/integration_test.rb
+++ b/actionpack/test/controller/integration_test.rb
@@ -930,6 +930,10 @@ end
 
 class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
   class FooController < ActionController::Base
+    def foos
+      render plain: "ok"
+    end
+
     def foos_json
       render json: params.permit(:foo)
     end
@@ -958,13 +962,30 @@ class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
   def test_encoding_as_json
     post_to_foos as: :json do
       assert_response :success
-      assert_match "foos_json.json", request.path
       assert_equal "application/json", request.content_type
+      assert_equal "application/json", request.accepts.first.to_s
+      assert_equal :json, request.format.ref
       assert_equal({ "foo" => "fighters" }, request.request_parameters)
       assert_equal({ "foo" => "fighters" }, response.parsed_body)
     end
   end
 
+  def test_doesnt_mangle_request_path
+    with_routing do |routes|
+      routes.draw do
+        ActiveSupport::Deprecation.silence do
+          post ":action" => FooController
+        end
+      end
+
+      post "/foos"
+      assert_equal "/foos", request.path
+
+      post "/foos_json", as: :json
+      assert_equal "/foos_json", request.path
+    end
+  end
+
   def test_encoding_as_without_mime_registration
     assert_raise ArgumentError do
       ActionDispatch::IntegrationTest.register_encoder :wibble
@@ -979,8 +1000,10 @@ class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
 
     post_to_foos as: :wibble do
       assert_response :success
-      assert_match "foos_wibble.wibble", request.path
+      assert_equal "/foos_wibble", request.path
       assert_equal "text/wibble", request.content_type
+      assert_equal "text/wibble", request.accepts.first.to_s
+      assert_equal :wibble, request.format.ref
       assert_equal Hash.new, request.request_parameters # Unregistered MIME Type can't be parsed.
       assert_equal "ok", response.parsed_body
     end