1 files changed, 153 insertions, 0 deletions
diff --git a/spec/requests/api/graphql/mutations/projects/sync_fork_spec.rb b/spec/requests/api/graphql/mutations/projects/sync_fork_spec.rb
new file mode 100644
index 00000000000..c5dc6f390d9
--- /dev/null
+++ b/spec/requests/api/graphql/mutations/projects/sync_fork_spec.rb
@@ -0,0 +1,153 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe "Sync project fork", feature_category: :source_code_management do
+  include GraphqlHelpers
+  include ProjectForksHelper
+  include ExclusiveLeaseHelpers
+
+  let_it_be(:source_project) { create(:project, :repository, :public) }
+  let_it_be(:current_user) { create(:user, maintainer_projects: [source_project]) }
+  let_it_be(:project, refind: true) { fork_project(source_project, current_user, { repository: true }) }
+  let_it_be(:target_branch) { project.default_branch }
+
+  let(:mutation) do
+    params = { project_path: project.full_path, target_branch: target_branch }
+
+    graphql_mutation(:project_sync_fork, params) do
+      <<-QL.strip_heredoc
+        details {
+          ahead
+          behind
+          isSyncing
+          hasConflicts
+        }
+        errors
+      QL
+    end
+  end
+
+  before do
+    source_project.change_head('feature')
+  end
+
+  context 'when synchronize_fork feature flag is disabled' do
+    before do
+      stub_feature_flags(synchronize_fork: false)
+    end
+
+    it 'does not call the sync service' do
+      expect(::Projects::Forks::SyncWorker).not_to receive(:perform_async)
+
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      expect(graphql_mutation_response(:project_sync_fork)).to eq(
+        {
+          'details' => nil,
+          'errors' => ['Feature flag is disabled']
+        })
+    end
+  end
+
+  context 'when the branch is protected', :use_clean_rails_redis_caching do
+    let_it_be(:protected_branch) do
+      create(:protected_branch, :no_one_can_push, project: project, name: target_branch)
+    end
+
+    it_behaves_like 'a mutation that returns a top-level access error'
+
+    it 'does not call the sync service' do
+      expect(::Projects::Forks::SyncWorker).not_to receive(:perform_async)
+
+      post_graphql_mutation(mutation, current_user: current_user)
+    end
+  end
+
+  context 'when the user does not have permission' do
+    let_it_be(:current_user) { create(:user) }
+
+    it_behaves_like 'a mutation that returns a top-level access error'
+
+    it 'does not call the sync service' do
+      expect(::Projects::Forks::SyncWorker).not_to receive(:perform_async)
+
+      post_graphql_mutation(mutation, current_user: current_user)
+    end
+  end
+
+  context 'when the user has permission' do
+    context 'and the sync service executes successfully', :sidekiq_inline do
+      it 'calls the sync service' do
+        expect(::Projects::Forks::SyncWorker).to receive(:perform_async).and_call_original
+
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(graphql_mutation_response(:project_sync_fork)).to eq(
+          {
+            'details' => { 'ahead' => 30, 'behind' => 0, "hasConflicts" => false, "isSyncing" => false },
+            'errors' => []
+          })
+      end
+    end
+
+    context 'and the sync service fails to execute' do
+      let(:target_branch) { 'markdown' }
+
+      def expect_error_response(message)
+        expect(::Projects::Forks::SyncWorker).not_to receive(:perform_async)
+
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(graphql_mutation_response(:project_sync_fork)['errors']).to eq([message])
+      end
+
+      context 'when fork details cannot be resolved' do
+        let_it_be(:project) { source_project }
+
+        it 'returns an error' do
+          expect_error_response('This branch of this project cannot be updated from the upstream')
+        end
+      end
+
+      context 'when the specified branch does not exist' do
+        let(:target_branch) { 'non-existent-branch' }
+
+        it 'returns an error' do
+          expect_error_response('Target branch does not exist')
+        end
+      end
+
+      context 'when the previous execution resulted in a conflict' do
+        it 'returns an error' do
+          expect_next_instance_of(::Projects::Forks::Details) do |instance|
+            expect(instance).to receive(:has_conflicts?).twice.and_return(true)
+          end
+
+          expect_error_response('The synchronization cannot happen due to the merge conflict')
+          expect(graphql_mutation_response(:project_sync_fork)['details']['hasConflicts']).to eq(true)
+        end
+      end
+
+      context 'when the request is rate limited' do
+        it 'returns an error' do
+          expect(Gitlab::ApplicationRateLimiter).to receive(:throttled?).and_return(true)
+
+          expect_error_response('This service has been called too many times.')
+        end
+      end
+
+      context 'when another fork sync is in progress' do
+        it 'returns an error' do
+          expect_next_instance_of(Projects::Forks::Details) do |instance|
+            lease = instance_double(Gitlab::ExclusiveLease, try_obtain: false, exists?: true)
+            expect(instance).to receive(:exclusive_lease).twice.and_return(lease)
+          end
+
+          expect_error_response('Another fork sync is already in progress')
+          expect(graphql_mutation_response(:project_sync_fork)['details']['isSyncing']).to eq(true)
+        end
+      end
+    end
+  end
+end