1 files changed, 14 insertions, 0 deletions
diff --git a/actionpack/test/dispatch/middleware_stack_test.rb b/actionpack/test/dispatch/middleware_stack_test.rb
index e5496c848b..f4e18308ae 100644
--- a/actionpack/test/dispatch/middleware_stack_test.rb
+++ b/actionpack/test/dispatch/middleware_stack_test.rb
@@ -73,4 +73,18 @@ class MiddlewareStackTest < ActiveSupport::TestCase
       end
     end
   end
+
+  test "lazy evaluates middleware class" do
+    assert_difference "@stack.size" do
+      @stack.use lambda { BazMiddleware }
+    end
+    assert_equal BazMiddleware, @stack.last.klass
+  end
+
+  test "lazy evaluates middleware arguments" do
+    assert_difference "@stack.size" do
+      @stack.use BazMiddleware, lambda { :foo }
+    end
+    assert_equal [:foo], @stack.last.send(:build_args)
+  end
 end