Add service to transfer group milestones

- Add new service that transfers milestones
from a group to a project
- Include new service in Projects transfer service
- Include FromUnion module in Milestone model
to use in transfer service
- Add specs for new milestones service
- Add specs for transferring milestones in
project transfer service

1 files changed, 12 insertions, 1 deletions

diff --git a/spec/services/projects/transfer_service_spec.rb b/spec/services/projects/transfer_service_spec.rb
index a47c10d991a..6b906f9372c 100644
--- a/spec/services/projects/transfer_service_spec.rb
+++ b/spec/services/projects/transfer_service_spec.rb
@@ -259,7 +259,7 @@ describe Projects::TransferService do
   end
 
   context 'missing group labels applied to issues or merge requests' do
-    it 'delegates tranfer to Labels::TransferService' do
+    it 'delegates transfer to Labels::TransferService' do
       group.add_owner(user)
 
       expect_any_instance_of(Labels::TransferService).to receive(:execute).once.and_call_original
@@ -268,6 +268,17 @@ describe Projects::TransferService do
     end
   end
 
+  context 'missing group milestones applied to issues or merge requests' do
+    it 'delegates transfer to Milestones::TransferService' do
+      group.add_owner(user)
+
+      expect(Milestones::TransferService).to receive(:new).with(user, project.group, project).and_call_original
+      expect_any_instance_of(Milestones::TransferService).to receive(:execute).once
+
+      transfer_project(project, user, group)
+    end
+  end
+
   context 'when hashed storage in use' do
     let(:hashed_project) { create(:project, :repository, namespace: user.namespace) }