1 files changed, 5 insertions, 0 deletions
diff --git a/actionpack/test/controller/parameters/parameters_permit_test.rb b/actionpack/test/controller/parameters/parameters_permit_test.rb
index ba191a7227..9c1828e9aa 100644
--- a/actionpack/test/controller/parameters/parameters_permit_test.rb
+++ b/actionpack/test/controller/parameters/parameters_permit_test.rb
@@ -160,6 +160,11 @@ class ParametersPermitTest < ActiveSupport::TestCase
     end
   end
 
+  test 'arrays are converted at most once' do
+    params = ActionController::Parameters.new(foo: [{}])
+    assert params[:foo].equal?(params[:foo])
+  end
+
   test "fetch doesnt raise ParameterMissing exception if there is a default" do
     assert_equal "monkey", @params.fetch(:foo, "monkey")
     assert_equal "monkey", @params.fetch(:foo) { "monkey" }