1 files changed, 22 insertions, 7 deletions
diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index 8bde82ccca..6a07a73d94 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -679,22 +679,37 @@ module ActionController
     # Returns a new <tt>ActionController::Parameters</tt> instance with the
     # results of running +block+ once for every key. The values are unchanged.
     def transform_keys(&block)
-      if block
-        new_instance_with_inherited_permitted_status(
-          @parameters.transform_keys(&block)
-        )
-      else
-        @parameters.transform_keys
-      end
+      return to_enum(:transform_keys) unless block_given?
+      new_instance_with_inherited_permitted_status(
+        @parameters.transform_keys(&block)
+      )
     end
 
     # Performs keys transformation and returns the altered
     # <tt>ActionController::Parameters</tt> instance.
     def transform_keys!(&block)
+      return to_enum(:transform_keys!) unless block_given?
       @parameters.transform_keys!(&block)
       self
     end
 
+    # Returns a new <tt>ActionController::Parameters</tt> instance with the
+    # results of running +block+ once for every key. This includes the keys
+    # from the root hash and from all nested hashes and arrays. The values are unchanged.
+    def deep_transform_keys(&block)
+      new_instance_with_inherited_permitted_status(
+        @parameters.deep_transform_keys(&block)
+      )
+    end
+
+    # Returns the <tt>ActionController::Parameters</tt> instance changing its keys.
+    # This includes the keys from the root hash and from all nested hashes and arrays.
+    # The values are unchanged.
+    def deep_transform_keys!(&block)
+      @parameters.deep_transform_keys!(&block)
+      self
+    end
+
     # Deletes a key-value pair from +Parameters+ and returns the value. If
     # +key+ is not found, returns +nil+ (or, with optional code block, yields
     # +key+ and returns the result). Cf. +#extract!+, which returns the