1 files changed, 76 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
new file mode 100644
index 0000000000..0ae464082d
--- /dev/null
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+module ActionDispatch
+  class Request
+    class Utils # :nodoc:
+      mattr_accessor :perform_deep_munge, default: true
+
+      def self.each_param_value(params, &block)
+        case params
+        when Array
+          params.each { |element| each_param_value(element, &block) }
+        when Hash
+          params.each_value { |value| each_param_value(value, &block) }
+        when String
+          block.call params
+        end
+      end
+
+      def self.normalize_encode_params(params)
+        if perform_deep_munge
+          NoNilParamEncoder.normalize_encode_params params
+        else
+          ParamEncoder.normalize_encode_params params
+        end
+      end
+
+      def self.check_param_encoding(params)
+        case params
+        when Array
+          params.each { |element| check_param_encoding(element) }
+        when Hash
+          params.each_value { |value| check_param_encoding(value) }
+        when String
+          unless params.valid_encoding?
+            # Raise Rack::Utils::InvalidParameterError for consistency with Rack.
+            # ActionDispatch::Request#GET will re-raise as a BadRequest error.
+            raise Rack::Utils::InvalidParameterError, "Invalid encoding for parameter: #{params.scrub}"
+          end
+        end
+      end
+
+      class ParamEncoder # :nodoc:
+        # Convert nested Hash to HashWithIndifferentAccess.
+        def self.normalize_encode_params(params)
+          case params
+          when Array
+            handle_array params
+          when Hash
+            if params.has_key?(:tempfile)
+              ActionDispatch::Http::UploadedFile.new(params)
+            else
+              params.each_with_object({}) do |(key, val), new_hash|
+                new_hash[key] = normalize_encode_params(val)
+              end.with_indifferent_access
+            end
+          else
+            params
+          end
+        end
+
+        def self.handle_array(params)
+          params.map! { |el| normalize_encode_params(el) }
+        end
+      end
+
+      # Remove nils from the params hash.
+      class NoNilParamEncoder < ParamEncoder # :nodoc:
+        def self.handle_array(params)
+          list = super
+          list.compact!
+          list
+        end
+      end
+    end
+  end
+end