backend/spec/requests/tags_deerjikists_spec.rb

@@ -226,6 +226,14 @@ RSpec.describe 'Tags deerjikists API', type: :request do
               [platform2, code2],
             )
         end
+
+        it 'locks the tag before replacing the complete list' do
+          expect_any_instance_of(Tag).to receive(:lock!).and_call_original
+
+          do_request
+
+          expect(response).to have_http_status(:ok)
+        end
       end
 
       context 'when tag already has deerjikists' do
@@ -299,6 +307,81 @@ RSpec.describe 'Tags deerjikists API', type: :request do
         end
       end
 
+      context 'when platform is outside the enum' do
+        let(:payload) do
+          [
+            { platform: 'invalid', code: code1 },
+          ]
+        end
+
+        it 'returns 422 with an indexed platform error without changing the list' do
+          Deerjikist.create!(platform: platform1, code: code1, tag: tag)
+
+          expect {
+            do_request
+          }.not_to change { Deerjikist.where(tag: tag).map { |d| [d.platform, d.code] } }
+
+          expect(response).to have_http_status(:unprocessable_entity)
+          expect(json.fetch('errors')).to include(
+            'deerjikists.0.platform' => [be_present],
+          )
+        end
+      end
+
+      context 'when a requested deerjikist belongs to another tag' do
+        let!(:other_tag) { create(:tag, category: :deerjikist) }
+        let!(:owned_deerjikist) do
+          Deerjikist.create!(platform: platform1, code: code1, tag: tag)
+        end
+        let!(:conflicting_deerjikist) do
+          Deerjikist.create!(platform: platform2, code: code2, tag: other_tag)
+        end
+        let(:payload) do
+          [
+            { platform: 'nico', code: 'new-code' },
+            { platform: platform2, code: code2 },
+          ]
+        end
+
+        before do
+          other_tag.tag_name.update!(name: 'existing-deerjikist')
+        end
+
+        it 'returns an indexed 422 error and rolls back the complete replacement' do
+          expect {
+            do_request
+          }.not_to change { Deerjikist.order(:platform, :code).pluck(:platform, :code, :tag_id) }
+
+          expect(response).to have_http_status(:unprocessable_entity)
+          expect(json.fetch('errors')).to include(
+            'deerjikists.1.code' => [include('existing-deerjikist')],
+          )
+          expect(owned_deerjikist.reload.tag_id).to eq(tag.id)
+          expect(conflicting_deerjikist.reload.tag_id).to eq(other_tag.id)
+        end
+      end
+
+      context 'when a requested deerjikist already belongs to the same tag' do
+        let!(:existing_deerjikist) do
+          Deerjikist.create!(platform: platform1, code: code1, tag: tag)
+        end
+        let(:payload) do
+          [
+            { platform: platform1, code: code1 },
+          ]
+        end
+
+        it 'keeps the existing row' do
+          expect {
+            do_request
+          }.not_to change { existing_deerjikist.reload.created_at }
+
+          expect(response).to have_http_status(:ok)
+          expect(Deerjikist.where(tag: tag).pluck(:platform, :code))
+            .to eq([[platform1, code1]])
+        end
+      end
+
       context 'when youtube code is handle' do
         let(:channel_id) { 'UCabcdefghijklmnopqrstuv' }
         let(:payload) do