Refactor prepare_hash

lib/multi_json/convertible_hash_keys.rb

@@ -15,18 +15,9 @@ def stringify_keys(hash)
     end
 
     def prepare_hash(hash, &key_modifier)
-      return hash unless key_modifier
-
-      case hash
-      when Array
-        hash.map { |value| prepare_hash(value, &key_modifier) }
-      when Hash
-        hash.each_with_object({}) do |(key, value), result|
-          result[yield(key)] = prepare_hash(value, &key_modifier)
-        end
-      else
-        handle_simple_objects(hash)
-      end
+      return handle_simple_objects(hash) unless hash.is_a?(Array) || hash.is_a?(Hash)
+      return handle_array(hash, &key_modifier) if hash.is_a?(Array)
+      handle_hash(hash, &key_modifier)
     end
 
     def handle_simple_objects(obj)
@@ -35,6 +26,17 @@ def handle_simple_objects(obj)
       obj.respond_to?(:to_s) ? obj.to_s : obj
     end
 
+    def handle_array(array, &key_modifier)
+      array.map { |value| prepare_hash(value, &key_modifier) }
+    end
+
+    def handle_hash(original_hash, &key_modifier)
+      original_hash.each_with_object({}) do |(key, value), result|
+        modified_key = key_modifier.call(key)
+        result[modified_key] = prepare_hash(value, &key_modifier)
+      end
+    end
+
     def simple_object?(obj)
       obj.is_a?(String) || obj.is_a?(Numeric) || obj == true || obj == false || obj.nil?
     end