1 files changed, 59 insertions, 9 deletions
diff --git a/spec/requests/api/group_milestones_spec.rb b/spec/requests/api/group_milestones_spec.rb
index 2b361f2b503..7ed6e1a295f 100644
--- a/spec/requests/api/group_milestones_spec.rb
+++ b/spec/requests/api/group_milestones_spec.rb
@@ -3,15 +3,65 @@
 require 'spec_helper'
 
 RSpec.describe API::GroupMilestones do
-  let(:user) { create(:user) }
-  let(:group) { create(:group, :private) }
-  let(:project) { create(:project, namespace: group) }
-  let!(:group_member) { create(:group_member, group: group, user: user) }
-  let!(:closed_milestone) { create(:closed_milestone, group: group, title: 'version1', description: 'closed milestone') }
-  let!(:milestone) { create(:milestone, group: group, title: 'version2', description: 'open milestone') }
-
-  it_behaves_like 'group and project milestones', "/groups/:id/milestones" do
-    let(:route) { "/groups/#{group.id}/milestones" }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:group) { create(:group, :private) }
+  let_it_be(:project) { create(:project, namespace: group) }
+  let_it_be(:group_member) { create(:group_member, group: group, user: user) }
+  let_it_be(:closed_milestone) { create(:closed_milestone, group: group, title: 'version1', description: 'closed milestone') }
+  let_it_be(:milestone) { create(:milestone, group: group, title: 'version2', description: 'open milestone') }
+  let(:route) { "/groups/#{group.id}/milestones" }
+
+  it_behaves_like 'group and project milestones', "/groups/:id/milestones"
+
+  describe 'GET /groups/:id/milestones' do
+    context 'when include_parent_milestones is true' do
+      let_it_be(:ancestor_group) { create(:group, :private) }
+      let_it_be(:ancestor_group_milestone) { create(:milestone, group: ancestor_group) }
+      let_it_be(:params) { { include_parent_milestones: true } }
+
+      before_all do
+        group.update(parent: ancestor_group)
+      end
+
+      shared_examples 'listing all milestones' do
+        it 'returns correct list of milestones' do
+          get api(route, user), params: params
+
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(json_response.size).to eq(milestones.size)
+          expect(json_response.map { |entry| entry["id"] }).to eq(milestones.map(&:id))
+        end
+      end
+
+      context 'when user has access to ancestor groups' do
+        let(:milestones) { [ancestor_group_milestone, milestone, closed_milestone] }
+
+        before do
+          ancestor_group.add_guest(user)
+          group.add_guest(user)
+        end
+
+        it_behaves_like 'listing all milestones'
+
+        context 'when iids param is present' do
+          let_it_be(:params) { { include_parent_milestones: true, iids: [milestone.iid] } }
+
+          it_behaves_like 'listing all milestones'
+        end
+      end
+
+      context 'when user has no access to ancestor groups' do
+        let(:user) { create(:user) }
+
+        before do
+          group.add_guest(user)
+        end
+
+        it_behaves_like 'listing all milestones' do
+          let(:milestones) { [milestone, closed_milestone] }
+        end
+      end
+    end
   end
 
   def setup_for_group