Add: #8 サークル投稿の転送 (#294)

* Add: `conversations`テーブルに`ancestor_status`プロパティ

* Fix test

* Fix test more

* Add: `limited_visibility`に`Reply`を追加、`context`のURI

* Add: 外部からの`context`受信処理

* Fix test

* Add: 公開範囲「返信」

* Fix test

* Fix: 返信に返信以外の公開範囲を設定できない問題

* Add: ローカル投稿時にメンション追加・他サーバーへの転送

* Fix test

* Fix test

* Test: ローカルスレッドへの返信投稿の転送

* Test: 未知のアカウントからのメンション

* Add: 編集・削除の連合に対応

* Remove: 重複テスト

* Fix: 改善

* Add: 編集削除の転送処理・返信なのにsilentなメンションでの通知

* Fix: リプライが第三者に届かない問題

* Add: `always_sign_unsafe`

* Add: Subject

* Remove space

* Fix: 他人のスレッドの送信先一覧を非表示

* Fix: おかしいコード

spec/policies/status_policy_spec.rb

@@ -115,6 +115,58 @@ RSpec.describe StatusPolicy, type: :model do
     end
   end
 
+  context 'with the permission of show_mentioned_users?' do
+    permissions :show_mentioned_users? do
+      it 'grants access when public and account is viewer' do
+        status.visibility = :public
+
+        expect(subject).to permit(status.account, status)
+      end
+
+      it 'grants access when public and account is not viewer' do
+        status.visibility = :public
+
+        expect(subject).to_not permit(bob, status)
+      end
+
+      it 'grants access when limited and no conversation ancestor_status and account is viewer' do
+        status.visibility = :limited
+        status.conversation = Fabricate(:conversation)
+
+        expect(subject).to permit(status.account, status)
+      end
+
+      it 'grants access when limited and my conversation and account is viewer' do
+        status.visibility = :limited
+        status.conversation = Fabricate(:conversation, ancestor_status: status)
+
+        expect(subject).to permit(status.account, status)
+      end
+
+      it 'grants access when limited and another conversation and account is viewer' do
+        status.visibility = :limited
+        status.conversation = Fabricate(:conversation, ancestor_status: Fabricate(:status, account: bob))
+
+        expect(subject).to_not permit(status.account, status)
+      end
+
+      it 'grants access when limited and viewer is mentioned' do
+        status.visibility = :limited
+        status.mentions = [Fabricate(:mention, account: bob)]
+
+        expect(subject).to_not permit(bob, status)
+      end
+
+      it 'grants access when limited and non-owner viewer is mentioned and mentions are loaded' do
+        status.visibility = :limited
+        status.mentions = [Fabricate(:mention, account: bob)]
+        status.mentions.load
+
+        expect(subject).to_not permit(bob, status)
+      end
+    end
+  end
+
   context 'with the permission of reblog?' do
     permissions :reblog? do
       it 'denies access when private' do