2 files changed, 14 insertions, 14 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/params_parser.rb b/actionpack/lib/action_dispatch/middleware/params_parser.rb
index ef55401015..18af0a583a 100644
--- a/actionpack/lib/action_dispatch/middleware/params_parser.rb
+++ b/actionpack/lib/action_dispatch/middleware/params_parser.rb
@@ -22,13 +22,9 @@ module ActionDispatch
     #
     # The +parsers+ argument can take Hash of parsers where key is identifying
     # content mime type, and value is a lambda that is going to process data.
-    def initialize(app, parsers = {})
-      @app = app
+    def self.new(app, parsers = {})
       ActionDispatch::Request.parameter_parsers = ActionDispatch::Request::DEFAULT_PARSERS.merge(parsers)
-    end
-
-    def call(env)
-      @app.call(env)
+      app
     end
   end
 end
diff --git a/actionpack/test/controller/webservice_test.rb b/actionpack/test/controller/webservice_test.rb
index b26f037c36..8b37c9599e 100644
--- a/actionpack/test/controller/webservice_test.rb
+++ b/actionpack/test/controller/webservice_test.rb
@@ -97,24 +97,28 @@ class WebServiceTest < ActionDispatch::IntegrationTest
   end
 
   def test_parsing_json_doesnot_rescue_exception
-    with_test_route_set do
-      with_params_parsers Mime::JSON => Proc.new { |data| raise Interrupt } do
-        assert_raises(Interrupt) do
-          post "/",
-            params: '{"title":"JSON"}}',
-            headers: { 'CONTENT_TYPE' => 'application/json' }
-        end
+    req = Class.new(ActionDispatch::Request) do
+      def params_parsers
+        { Mime::JSON => Proc.new { |data| raise Interrupt } }
       end
+
+      def content_length; get_header('rack.input').length; end
+    end.new({ 'rack.input' => StringIO.new('{"title":"JSON"}}'), 'CONTENT_TYPE' => 'application/json' })
+
+    assert_raises(Interrupt) do
+      req.request_parameters
     end
   end
 
   private
     def with_params_parsers(parsers = {})
       old_session = @integration_session
-      @app = ActionDispatch::ParamsParser.new(app.routes, parsers)
+      original_parsers = ActionDispatch::Request.parameter_parsers
+      ActionDispatch::Request.parameter_parsers = original_parsers.merge parsers
       reset!
       yield
     ensure
+      ActionDispatch::Request.parameter_parsers = original_parsers
       @integration_session = old_session
     end