Fixes syntax error

app/helpers/diff_helper.rb

@@ -137,7 +137,7 @@ module DiffHelper
     # Always use HTML to handle case where JSON diff rendered this button
     params_copy.delete(:format)
 
-    link_to url_for(params_copy), id: "#{name}-diff-btn", class: (selected ? 'btn active' : 'btn'), data: {view_type: name} do
+    link_to url_for(params_copy), id: "#{name}-diff-btn", class: (selected ? 'btn active' : 'btn'), data: { view_type: name } do
       title
     end
   end