#55

backend/app/representations/post_repr.rb

@@ -91,7 +91,7 @@ module PostRepr
         post
         .post_tags
         .reject { _1.tag.deprecated? }
-        .sort_by { _1.tag.name(language_code) }
+        .sort_by { TagRepr.name_for(_1.tag, language_code) }
         .map { |post_tag|
           TagRepr.inline(post_tag.tag, language_code:).merge(
               'children' => [],

backend/app/representations/tag_repr.rb

@@ -8,14 +8,18 @@ module TagRepr
   module_function
 
   def base tag, language_code: 'ja'
-    tag.as_json(BASE).merge(name: tag.name(language_code),
+    tag.as_json(BASE).merge(name: name_for(tag, language_code),
                             aliases: tag.snapshot_aliases(language_code),
                             parents: tag.parents.map { inline(_1, language_code:) })
   end
 
   def inline tag, language_code: 'ja'
-    tag.as_json(BASE).merge(name: tag.name(language_code), aliases: [], parents: [])
+    tag.as_json(BASE).merge(name: name_for(tag, language_code), aliases: [], parents: [])
   end
 
   def many(tags, language_code: 'ja') = tags.map { |tag| base(tag, language_code:) }
+
+  def name_for tag, language_code
+    tag.name(language_code) || (tag.system? ? tag.name('ja') : nil)
+  end
 end