backend/app/controllers/posts_controller.rb

@@ -36,7 +36,7 @@ class PostsController < ApplicationController
 
     render json: { posts: posts.map { |post|
       post.as_json(include: { tags: { only: [:id, :category, :post_count],
-                                      methods: [:name] } }).tap do |json|
+                                      methods: [:name, :has_wiki] } }).tap do |json|
         json['thumbnail'] =
             if post.thumbnail.attached?
               rails_storage_proxy_url(post.thumbnail, only_path: false)
@@ -59,7 +59,7 @@ class PostsController < ApplicationController
 
     render json: (post
                   .as_json(include: { tags: { only: [:id, :category, :post_count],
-                                              methods: [:name] } })
+                                              methods: [:name, :has_wiki] } })
                   .merge(viewed:))
   end
 
@@ -100,7 +100,7 @@ class PostsController < ApplicationController
       tags = Tag.expand_parent_tags(tags)
       sync_post_tags!(post, tags)
       render json: post.as_json(include: { tags: { only: [:id, :category, :post_count],
-                                                   methods: [:name] } }),
+                                                   methods: [:name, :has_wiki] } }),
              status: :created
     else
       render json: { errors: post.errors.full_messages }, status: :unprocessable_entity
@@ -162,7 +162,7 @@ class PostsController < ApplicationController
     pts.each do |pt|
       events << Event.new(
           post:         pt.post,
-          tag:          pt.tag.as_json(only: [:id, :category], methods: [:name]),
+          tag:          pt.tag.as_json(only: [:id, :category], methods: [:name, :has_wiki]),
           user:         pt.created_user && { id: pt.created_user.id, name: pt.created_user.name },
           change_type:  'add',
           timestamp:    pt.created_at)
@@ -170,7 +170,7 @@ class PostsController < ApplicationController
       if pt.discarded_at
         events << Event.new(
             post:         pt.post,
-            tag:          pt.tag.as_json(only: [:id, :category], methods: [:name]),
+            tag:          pt.tag.as_json(only: [:id, :category], methods: [:name, :has_wiki]),
             user:         pt.deleted_user && { id: pt.deleted_user.id, name: pt.deleted_user.name },
             change_type:  'remove',
             timestamp:    pt.discarded_at)
@@ -255,7 +255,7 @@ class PostsController < ApplicationController
 
       if path.include?(tag_id)
         return tag.as_json(only: [:id, :category, :post_count],
-                           methods: [:name]).merge(children: [])
+                           methods: [:name, :has_wiki]).merge(children: [])
       end
 
       if memo.key?(tag_id)
@@ -268,7 +268,7 @@ class PostsController < ApplicationController
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
       memo[tag_id] = tag.as_json(only: [:id, :category, :post_count],
-                                 methods: [:name]).merge(children:)
+                                 methods: [:name, :has_wiki]).merge(children:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }

backend/spec/requests/posts_spec.rb

@@ -54,9 +54,9 @@ RSpec.describe 'Posts API', type: :request do
       # 全postの全tagが name を含むこと
       expect(posts).not_to be_empty
       posts.each do |p|
-        expect(p["tags"]).to be_an(Array)
-        p["tags"].each do |t|
-          expect(t).to include("name", "category")
+        expect(p['tags']).to be_an(Array)
+        p['tags'].each do |t|
+          expect(t).to include('name', 'category', 'has_wiki')
         end
       end
       expect(json['count']).to be_an(Integer)
@@ -71,11 +71,19 @@ RSpec.describe 'Posts API', type: :request do
         get "/posts", params: { tags: "spec_tag" }
 
         expect(response).to have_http_status(:ok)
-        ids = json.fetch("posts").map { |p| p["id"] }
+        posts = json.fetch('posts')
+        ids = posts.map { |p| p['id'] }
 
         expect(ids).to include(hit_post.id)
         expect(ids).not_to include(miss_post.id)
         expect(json['count']).to be_an(Integer)
+
+        posts.each do |p|
+          expect(p['tags']).to be_an(Array)
+          p['tags'].each do |t|
+            expect(t).to include('name', 'category', 'has_wiki')
+          end
+        end
       end
 
       it "returns empty posts when nothing matches" do
@@ -104,7 +112,7 @@ RSpec.describe 'Posts API', type: :request do
 
         # show は build_tag_tree_for を使うので、tags はツリー形式（children 付き）
         node = json['tags'][0]
-        expect(node).to include('id', 'name', 'category', 'post_count', 'children')
+        expect(node).to include('id', 'name', 'category', 'post_count', 'children', 'has_wiki')
         expect(node['name']).to eq('spec_tag')
 
         expect(json).to have_key('related')

frontend/src/components/TagLink.tsx

@@ -32,7 +32,15 @@ export default (({ tag,
 		   ...props }: Props) => {
   const [havingWiki, setHavingWiki] = useState (true)
 
-  const wikiExists = async (tagName: string) => {
+  const wikiExists = async (tag: Tag) => {
+    if ('hasWiki' in tag)
+      {
+	setHavingWiki (tag.hasWiki)
+	return
+      }
+
+    const tagName = (tag as Tag).name
+
     try
     {
       await axios.get (`${ API_BASE_URL }/wiki/title/${ encodeURIComponent (tagName) }/exists`)
@@ -48,7 +56,7 @@ export default (({ tag,
     if (!(linkFlg) || !(withWiki))
       return
 
-    wikiExists (tag.name)
+    wikiExists (tag)
   }, [tag.name, linkFlg, withWiki])
 
   const spanClass = cn (

frontend/src/types.ts

@@ -48,6 +48,7 @@ export type Tag = {
     name:       string
     category:   Category
     postCount:  number
+    hasWiki:    boolean
     children?:  Tag[] }
 
 export type User = {