2 files changed, 18 insertions, 0 deletions
diff --git a/actionpack/test/controller/parameters/accessors_test.rb b/actionpack/test/controller/parameters/accessors_test.rb
index 7b9b716a42..cb49eeb1b7 100644
--- a/actionpack/test/controller/parameters/accessors_test.rb
+++ b/actionpack/test/controller/parameters/accessors_test.rb
@@ -213,6 +213,15 @@ class ParametersAccessorsTest < ActiveSupport::TestCase
     assert_kind_of ActionController::Parameters, @params.transform_keys!.each { |k| k }
   end
 
+  test "deep_transform_keys retains permitted status" do
+    @params.permit!
+    assert_predicate @params.deep_transform_keys { |k| k }, :permitted?
+  end
+
+  test "deep_transform_keys retains unpermitted status" do
+    assert_not_predicate @params.deep_transform_keys { |k| k }, :permitted?
+  end
+
   test "transform_values retains permitted status" do
     @params.permit!
     assert_predicate @params.transform_values { |v| v }, :permitted?
diff --git a/actionpack/test/controller/parameters/mutators_test.rb b/actionpack/test/controller/parameters/mutators_test.rb
index 312b1e5b27..31ee7964f5 100644
--- a/actionpack/test/controller/parameters/mutators_test.rb
+++ b/actionpack/test/controller/parameters/mutators_test.rb
@@ -118,4 +118,13 @@ class ParametersMutatorsTest < ActiveSupport::TestCase
   test "transform_values! retains unpermitted status" do
     assert_not_predicate @params.transform_values! { |v| v }, :permitted?
   end
+
+  test "deep_transform_keys! retains permitted status" do
+    @params.permit!
+    assert_predicate @params.deep_transform_keys! { |k| k }, :permitted?
+  end
+
+  test "deep_transform_keys! retains unpermitted status" do
+    assert_not_predicate @params.deep_transform_keys! { |k| k }, :permitted?
+  end
 end