lib/grape/request.rb in grape-1.8.0 vs lib/grape/request.rb in grape-2.0.0

@@ -44,10 +44,16 @@
           headers[transformed_header] = v
         end
       end
     end
 
-    def transform_header(header)
-      -header[5..].split('_').each(&:capitalize!).join('-')
+    if Grape.lowercase_headers?
+      def transform_header(header)
+        -header[5..].tr('_', '-').downcase
+      end
+    else
+      def transform_header(header)
+        -header[5..].split('_').map(&:capitalize).join('-')
+      end
     end
   end
 end