#20 テスト・ケースのみ追記

backend/spec/requests/posts_spec.rb

@@ -30,6 +30,7 @@ RSpec.describe 'Posts API', type: :request do
     let!(:tag) { Tag.create!(tag_name:, category: "general") }
     let!(:tag_name2) { TagName.create!(name: 'unko') }
     let!(:tag2) { Tag.create!(tag_name: tag_name2, category: 'deerjikist') }
+    let!(:alias_tag_name) { TagName.create!(name: 'manko', canonical: tag_name) }
 
     let!(:hit_post) do
       Post.create!(uploaded_user: user, title: "hello spec world",
@@ -86,6 +87,25 @@ RSpec.describe 'Posts API', type: :request do
         end
       end
 
+      it "filters posts by q (hit case by alias)" do
+        get "/posts", params: { tags: "manko" }
+
+        expect(response).to have_http_status(:ok)
+        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
         get "/posts", params: { tags: "no_such_keyword_12345" }
 
@@ -167,6 +187,26 @@ RSpec.describe 'Posts API', type: :request do
       expect(json['tags'][0]).to have_key('name')
     end
 
+    it '201 and creates post + tags when member and tags have aliases' do
+      sign_in_as(member)
+
+      post '/posts', params: {
+        title: 'new post',
+        url: 'https://example.com/new',
+        tags: 'manko', # 既存タグ名を投げる
+        thumbnail: dummy_upload
+      }
+
+      expect(response).to have_http_status(:created)
+      expect(json).to include('id', 'title', 'url')
+
+      # tags が name を含むこと（API 側の serialization が正しいこと）
+      expect(json).to have_key('tags')
+      expect(json['tags']).to be_an(Array)
+      expect(json['tags'][0]).to have_key('name')
+      expect(json['tags'][0]['name']).to eq('spec_tag')
+    end
+
     context "when nico tag already exists in tags" do
       before do
         Tag.find_or_create_by!(tag_name: TagName.find_or_create_by!(name: 'nico:nico_tag'),

backend/spec/requests/tags_spec.rb

@@ -5,6 +5,7 @@ require 'rails_helper'
 RSpec.describe 'Tags API', type: :request do
   let!(:tn) { TagName.create!(name: 'spec_tag') }
   let!(:tag) { Tag.create!(tag_name: tn, category: 'general') }
+  let!(:alias_tn) { TagName.create!(name: 'unko', canonical: tn) }
 
   describe 'GET /tags' do
     it 'returns tags with name' do
@@ -56,6 +57,20 @@ RSpec.describe 'Tags API', type: :request do
 
       expect(json).to be_an(Array)
       expect(json.map { |t| t['name'] }).to include('spec_tag')
+      t = json.find { |t| t['name'] == 'spec_tag' }
+      expect(t).to have_key('matched_alias')
+      expect(t['matched_alias']).to be(nil)
+    end
+
+    it 'returns matching canonical tags by q with aliases' do
+      get '/tags/autocomplete', params: { q: 'unk' }
+
+      expect(response).to have_http_status(:ok)
+
+      expect(json).to be_an(Array)
+      expect(json.map { |t| t['name'] }).to include('spec_tag')
+      t = json.find { |t| t['name'] == 'spec_tag' }
+      expect(t['matched_alias']).to eq('unko')
     end
   end