Rewrite test setup to make things clearer

The tests were very hard to follow because of the naming of objects
and the one big setup at the top

This sets up the required objects within the tests so that the intent
of the tests are clearer

spec/services/labels/transfer_service_spec.rb

@@ -4,65 +4,72 @@ require 'spec_helper'
 
 describe Labels::TransferService do
   describe '#execute' do
-    let(:user)    { create(:admin) }
-    let(:group_1) { create(:group) }
-    let(:group_2) { create(:group) }
-    let(:group_3) { create(:group) }
-    let(:project_1) { create(:project, namespace: group_2) }
-    let(:project_2) { create(:project, namespace: group_3) }
-    let(:project_3) { create(:project, namespace: group_1) }
-
-    let(:group_label_1) { create(:group_label, group: group_1, name: 'Group Label 1') }
-    let(:group_label_2) { create(:group_label, group: group_1, name: 'Group Label 2') }
-    let(:group_label_3) { create(:group_label, group: group_1, name: 'Group Label 3') }
-    let(:group_label_4) { create(:group_label, group: group_2, name: 'Group Label 4') }
-    let(:group_label_5) { create(:group_label, group: group_3, name: 'Group Label 5') }
-    let(:project_label_1) { create(:label, project: project_1, name: 'Project Label 1') }
-
-    subject(:service) { described_class.new(user, group_1, project_1) }
-
-    before do
-      create(:labeled_issue, project: project_1, labels: [group_label_1])
-      create(:labeled_issue, project: project_1, labels: [group_label_4])
-      create(:labeled_issue, project: project_1, labels: [project_label_1])
-      create(:labeled_issue, project: project_2, labels: [group_label_5])
-      create(:labeled_issue, project: project_3, labels: [group_label_1])
-      create(:labeled_merge_request, source_project: project_1, labels: [group_label_1, group_label_2])
-      create(:labeled_merge_request, source_project: project_2, labels: [group_label_5])
-    end
+    let_it_be(:user) { create(:admin) }
+
+    let_it_be(:old_group_ancestor) { create(:group) }
+    let_it_be(:old_group) { create(:group, parent: old_group_ancestor) }
+
+    let_it_be(:new_group) { create(:group) }
+
+    let_it_be(:project) { create(:project, :repository, group: new_group) }
+
+    subject(:service) { described_class.new(user, old_group, project) }
+
+    it 'recreates the missing group labels at project level and assigns them to the issuables' do
+      old_group_label_1 = create(:group_label, group: old_group)
+      old_group_label_2 = create(:group_label, group: old_group)
+
+      labeled_issue = create(:labeled_issue, project: project, labels: [old_group_label_1])
+      labeled_merge_request = create(:labeled_merge_request, source_project: project, labels: [old_group_label_2])
 
-    it 'recreates the missing group labels at project level' do
-      expect { service.execute }.to change(project_1.labels, :count).by(2)
+      expect { service.execute }.to change(project.labels, :count).by(2)
+      expect(labeled_issue.reload.labels).to contain_exactly(project.labels.find_by_title(old_group_label_1.title))
+      expect(labeled_merge_request.reload.labels).to contain_exactly(project.labels.find_by_title(old_group_label_2.title))
     end
 
     it 'recreates label priorities related to the missing group labels' do
-      create(:label_priority, project: project_1, label: group_label_1, priority: 1)
+      old_group_label = create(:group_label, group: old_group)
+      create(:labeled_issue, project: project, labels: [old_group_label])
+      create(:label_priority, project: project, label: old_group_label, priority: 1)
 
       service.execute
 
-      new_project_label = project_1.labels.find_by(title: group_label_1.title)
-      expect(new_project_label.id).not_to eq group_label_1.id
+      new_project_label = project.labels.find_by(title: old_group_label.title)
+      expect(new_project_label.id).not_to eq old_group_label.id
       expect(new_project_label.priorities).not_to be_empty
     end
 
     it 'does not recreate missing group labels that are not applied to issues or merge requests' do
+      old_group_label = create(:group_label, group: old_group)
+
       service.execute
 
-      expect(project_1.labels.where(title: group_label_3.title)).to be_empty
+      expect(project.labels.where(title: old_group_label.title)).to be_empty
     end
 
     it 'does not recreate missing group labels that already exist in the project group' do
+      old_group_label = create(:group_label, group: old_group)
+      labeled_issue = create(:labeled_issue, project: project, labels: [old_group_label])
+
+      new_group_label = create(:group_label, group: new_group, title: old_group_label.title)
+
       service.execute
 
-      expect(project_1.labels.where(title: group_label_4.title)).to be_empty
+      expect(project.labels.where(title: old_group_label.title)).to be_empty
+      expect(labeled_issue.reload.labels).to contain_exactly(new_group_label)
     end
 
     it 'updates only label links in the given project' do
-      service.execute
+      old_group_label = create(:group_label, group: old_group)
+      other_project = create(:project, group: old_group)
+
+      labeled_issue = create(:labeled_issue, project: project, labels: [old_group_label])
+      other_project_labeled_issue = create(:labeled_issue, project: other_project, labels: [old_group_label])
 
-      targets = LabelLink.where(label_id: group_label_1.id).map(&:target)
+      service.execute
 
-      expect(targets).to eq(project_3.issues)
+      expect(labeled_issue.reload.labels).not_to include(old_group_label)
+      expect(other_project_labeled_issue.reload.labels).to contain_exactly(old_group_label)
     end
   end
 end