2 files changed, 45 insertions, 0 deletions
diff --git a/spec/benchmarks/models/milestone_spec.rb b/spec/benchmarks/models/milestone_spec.rb
new file mode 100644
index 00000000000..a94afc4c40d
--- /dev/null
+++ b/spec/benchmarks/models/milestone_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe Milestone, benchmark: true do
+  describe '#sort_issues' do
+    let(:milestone) { create(:milestone) }
+
+    let(:issue1) { create(:issue, milestone: milestone) }
+    let(:issue2) { create(:issue, milestone: milestone) }
+    let(:issue3) { create(:issue, milestone: milestone) }
+
+    let(:issue_ids) { [issue3.id, issue2.id, issue1.id] }
+
+    benchmark_subject { milestone.sort_issues(issue_ids) }
+
+    it { is_expected.to iterate_per_second(500) }
+  end
+end
diff --git a/spec/models/milestone_spec.rb b/spec/models/milestone_spec.rb
index c88d5349663..77c58627322 100644
--- a/spec/models/milestone_spec.rb
+++ b/spec/models/milestone_spec.rb
@@ -140,4 +140,32 @@ describe Milestone do
     end
   end
 
+  describe '#sort_issues' do
+    let(:milestone) { create(:milestone) }
+
+    let(:issue1) { create(:issue, milestone: milestone, position: 1) }
+    let(:issue2) { create(:issue, milestone: milestone, position: 2) }
+    let(:issue3) { create(:issue, milestone: milestone, position: 3) }
+    let(:issue4) { create(:issue, position: 42) }
+
+    it 'sorts the given issues' do
+      milestone.sort_issues([issue3.id, issue2.id, issue1.id])
+
+      issue1.reload
+      issue2.reload
+      issue3.reload
+
+      expect(issue1.position).to eq(3)
+      expect(issue2.position).to eq(2)
+      expect(issue3.position).to eq(1)
+    end
+
+    it 'ignores issues not part of the milestone' do
+      milestone.sort_issues([issue3.id, issue2.id, issue1.id, issue4.id])
+
+      issue4.reload
+
+      expect(issue4.position).to eq(42)
+    end
+  end
 end