Use ruby2_keywords + send_keyword_hash for ActionDispatch::MiddlewareStack

* Makes it explicit where the conversion can happen.

Author: eregon

actionpack/lib/action_dispatch/middleware/stack.rb

@@ -3,6 +3,17 @@
 require "active_support/inflector/methods"
 require "active_support/dependencies"
 
+class BasicObject
+  alias_method :send_keyword_hash, :__send__ unless respond_to?(:send_keyword_hash)
+end
+
+class Module
+  unless respond_to?(:ruby2_keywords, true)
+    def self.ruby2_keywords(*)
+    end
+  end
+end
+
 module ActionDispatch
   class MiddlewareStack
     class Middleware
@@ -34,7 +45,7 @@ def inspect
       end
 
       def build(app)
-        klass.new(app, *args, &block)
+        klass.send_keyword_hash(:new, app, *args, &block)
       end
 
       def build_instrumented(app)
@@ -88,27 +99,27 @@ def [](i)
       middlewares[i]
     end
 
-    def unshift(klass, *args, &block)
+    ruby2_keywords def unshift(klass, *args, &block)
       middlewares.unshift(build_middleware(klass, args, block))
     end
 
     def initialize_copy(other)
       self.middlewares = other.middlewares.dup
     end
 
-    def insert(index, klass, *args, &block)
+    ruby2_keywords def insert(index, klass, *args, &block)
       index = assert_index(index, :before)
       middlewares.insert(index, build_middleware(klass, args, block))
     end
 
     alias_method :insert_before, :insert
 
-    def insert_after(index, *args, &block)
+    ruby2_keywords def insert_after(index, *args, &block)
       index = assert_index(index, :after)
       insert(index + 1, *args, &block)
     end
 
-    def swap(target, *args, &block)
+    ruby2_keywords def swap(target, *args, &block)
       index = assert_index(target, :before)
       insert(index, *args, &block)
       middlewares.delete_at(index + 1)
@@ -118,7 +129,7 @@ def delete(target)
       middlewares.delete_if { |m| m.klass == target }
     end
 
-    def use(klass, *args, &block)
+    ruby2_keywords def use(klass, *args, &block)
       middlewares.push(build_middleware(klass, args, block))
     end