1 files changed, 7 insertions, 4 deletions
diff --git a/actionpack/test/controller/request/test_request_test.rb b/actionpack/test/controller/request/test_request_test.rb
index e5d698d5c2..fa049fbc9f 100644
--- a/actionpack/test/controller/request/test_request_test.rb
+++ b/actionpack/test/controller/request/test_request_test.rb
@@ -1,12 +1,16 @@
-require 'abstract_unit'
-require 'stringio'
+require "abstract_unit"
+require "stringio"
 
 class ActionController::TestRequestTest < ActionController::TestCase
-
   def test_test_request_has_session_options_initialized
     assert @request.session_options
   end
 
+  def test_mutating_session_options_does_not_affect_default_options
+    @request.session_options[:myparam] = 123
+    assert_equal nil, ActionController::TestSession::DEFAULT_OPTIONS[:myparam]
+  end
+
   ActionDispatch::Session::AbstractStore::DEFAULT_OPTIONS.each_key do |option|
     test "rack default session options #{option} exists in session options and is default" do
       assert_equal(ActionDispatch::Session::AbstractStore::DEFAULT_OPTIONS[option],
@@ -19,5 +23,4 @@ class ActionController::TestRequestTest < ActionController::TestCase
                    "Missing rack session option #{option} in request.session_options")
     end
   end
-
 end