#422

backend/app/controllers/tag_descriptions_controller.rb

@@ -14,7 +14,7 @@ class TagDescriptionsController < ApplicationController
     render json: representation(description)
   end
 
-  def create
+  def update
     return head :unauthorized unless current_user
     return head :forbidden unless current_user.gte_member?
 
@@ -24,39 +24,23 @@ class TagDescriptionsController < ApplicationController
     tag = Tag.find_by(id: params[:id])
     return head :not_found unless tag
 
-    if TagDescription.exists?(tag:, language_code: 'ja')
-      return render_unprocessable_entity('説明はすでに存在します．')
+    description = TagDescription.find_by(tag:, language_code: 'ja')
+
+    if description
+      TagDescriptionOperation.update!(tag:, body:, updated_by_user: current_user)
+      description.reload
+      render json: representation(description)
+    else
+      TagDescriptionOperation.create!(tag:, body:, created_by_user: current_user)
+      description = TagDescription.find_by!(tag:, language_code: 'ja')
+      render json: representation(description), status: :created
     end
-
-    TagDescriptionOperation.create!(tag:, body:, created_by_user: current_user)
-    description = TagDescription.find_by!(tag:, language_code: 'ja')
-
-    render json: representation(description), status: :created
   rescue ActiveRecord::RecordInvalid => e
     render_validation_error e.record
   rescue ActiveRecord::RecordNotUnique
     render_record_not_unique
   end
 
-  def update
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-
-    body = params[:body].to_s
-    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
-
-    description = TagDescription.find_by(tag_id: params[:id], language_code: 'ja')
-    return create unless description
-
-    TagDescriptionOperation.update!(
-        tag: description.tag, body:, updated_by_user: current_user)
-    description.reload
-
-    render json: representation(description)
-  rescue ActiveRecord::RecordInvalid => e
-    render_validation_error e.record
-  end
-
   private
 
   def representation description

backend/app/controllers/wiki_pages_controller.rb

@@ -2,6 +2,10 @@ class WikiPagesController < ApplicationController
   rescue_from Wiki::Commit::Conflict, with: :render_wiki_conflict
 
   def index
+    # 互換性のための化石リソース
+    # TODO: ヘルプおよびタグ・グループ追加後に，
+    # TODO: タグ説明とヘルプ、タグ・グループから取得する作りに変更する．
+    #
     title = params[:title].to_s.strip
     descriptions = TagDescription.where(language_code: 'ja')
         .includes(tag: :tag_names)