Fix snippet repository storage move API when snippet does not exist

changelogs/unreleased/fj-fix-api-when-snippet-does-not-exist.yml

+---
+title: Fix snippet repository storage move API when snippet does not exist
+merge_request: 53211
+author:
+type: fixed

lib/api/snippet_repository_storage_moves.rb

@@ -58,9 +58,14 @@ module API
     resource :snippets do
       helpers do
         def user_snippet
-          Snippet.find_by(id: params[:id])  # rubocop: disable CodeReuse/ActiveRecord
+          @user_snippet ||= Snippet.find_by(id: params[:id]) # rubocop: disable CodeReuse/ActiveRecord
         end
       end
+
+      before do
+        not_found!('Snippet') unless user_snippet
+      end
+
       desc 'Get a list of all snippets repository storage moves' do
         detail 'This feature was introduced in GitLab 13.8.'
         success Entities::SnippetRepositoryStorageMove

spec/support/shared_examples/requests/api/repository_storage_moves_shared_examples.rb

@@ -85,14 +85,37 @@ RSpec.shared_examples 'repository_storage_moves API' do |container_type|
   end
 
   describe "GET /#{container_type}/:id/repository_storage_moves" do
-    it_behaves_like 'get container repository storage move list' do
-      let(:url) { "/#{container_type}/#{container.id}/repository_storage_moves" }
+    let(:container_id) { container.id }
+    let(:url) { "/#{container_type}/#{container_id}/repository_storage_moves" }
+
+    it_behaves_like 'get container repository storage move list'
+
+    context 'non-existent container' do
+      let(:container_id) { non_existing_record_id }
+
+      it 'returns not found' do
+        get api(url, user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
     end
   end
 
   describe "GET /#{container_type}/:id/repository_storage_moves/:repository_storage_move_id" do
-    it_behaves_like 'get single container repository storage move' do
-      let(:url) { "/#{container_type}/#{container.id}/repository_storage_moves/#{repository_storage_move_id}" }
+    let(:container_id) { container.id }
+    let(:url) { "/#{container_type}/#{container_id}/repository_storage_moves/#{repository_storage_move_id}" }
+
+    it_behaves_like 'get single container repository storage move'
+
+    context 'non-existent container' do
+      let(:container_id) { non_existing_record_id }
+      let(:repository_storage_move_id) { storage_move.id }
+
+      it 'returns not found' do
+        get api(url, user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
     end
   end
 
@@ -109,7 +132,8 @@ RSpec.shared_examples 'repository_storage_moves API' do |container_type|
   end
 
   describe "POST /#{container_type}/:id/repository_storage_moves" do
-    let(:url) { "/#{container_type}/#{container.id}/repository_storage_moves" }
+    let(:container_id) { container.id }
+    let(:url) { "/#{container_type}/#{container_id}/repository_storage_moves" }
     let(:destination_storage_name) { 'test_second_storage' }
 
     def create_container_repository_storage_move
@@ -154,6 +178,16 @@ RSpec.shared_examples 'repository_storage_moves API' do |container_type|
         expect(json_response['destination_storage_name']).to be_present
       end
     end
+
+    context 'when container does not exist' do
+      let(:container_id) { non_existing_record_id }
+
+      it 'returns not found' do
+        create_container_repository_storage_move
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
   end
 
   describe "POST /#{container_type.singularize}_repository_storage_moves" do