Change request method to a GET when passing failed requests to config.exceptions_app

actionpack/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Unreleased
 
+*   Change the request method to a `GET` when passing failed requests down to `config.exceptions_app`.
+
+    *Alex Robbin*
+
 *   Add `redirect_back_or_to(fallback_location, **)` as a more aesthetically pleasing version of `redirect_back fallback_location:, **`.
     The old method name is retained without explicit deprecation.
 

actionpack/lib/action_dispatch/middleware/show_exceptions.rb

@@ -46,7 +46,9 @@ def render_exception(request, exception)
         status  = wrapper.status_code
         request.set_header "action_dispatch.exception", wrapper.unwrapped_exception
         request.set_header "action_dispatch.original_path", request.path_info
+        request.set_header "action_dispatch.original_request_method", request.raw_request_method
         request.path_info = "/#{status}"
+        request.request_method = "GET"
         response = @exceptions_app.call(request.env)
         response[1]["X-Cascade"] == "pass" ? pass_response(status) : response
       rescue Exception => failsafe_error

railties/test/application/middleware/exceptions_test.rb

@@ -51,6 +51,20 @@ def index
       assert_equal 405, last_response.status
     end
 
+    test "renders unknown http methods as 405 when routes are used as the custom exceptions app" do
+      app_file "config/routes.rb", <<-RUBY
+        Rails.application.routes.draw do
+        end
+      RUBY
+
+      add_to_config "config.exceptions_app = self.routes"
+
+      app.config.action_dispatch.show_exceptions = true
+
+      request "/", { "REQUEST_METHOD" => "NOT_AN_HTTP_METHOD" }
+      assert_equal 405, last_response.status
+    end
+
     test "uses custom exceptions app" do
       add_to_config <<-RUBY
         config.exceptions_app = lambda do |env|