Add ApplicationRecord#safe_ensure_unique method

Port of https://dev.gitlab.org/gitlab/gitlab-ee/merge_requests/866
to CE excluding the migration and service changes as they don't
apply to CE.

1 files changed, 19 insertions, 0 deletions

diff --git a/spec/models/application_record_spec.rb b/spec/models/application_record_spec.rb
index fd25132ed3a..cc90a998d3f 100644
--- a/spec/models/application_record_spec.rb
+++ b/spec/models/application_record_spec.rb
@@ -11,6 +11,25 @@ describe ApplicationRecord do
     end
   end
 
+  describe '.safe_ensure_unique' do
+    let(:model) { build(:suggestion) }
+    let(:klass) { model.class }
+
+    before do
+      allow(model).to receive(:save).and_raise(ActiveRecord::RecordNotUnique)
+    end
+
+    it 'returns false when ActiveRecord::RecordNotUnique is raised' do
+      expect(model).to receive(:save).once
+      expect(klass.safe_ensure_unique { model.save }).to be_falsey
+    end
+
+    it 'retries based on retry count specified' do
+      expect(model).to receive(:save).exactly(3).times
+      expect(klass.safe_ensure_unique(retries: 2) { model.save }).to be_falsey
+    end
+  end
+
   describe '.safe_find_or_create_by' do
     it 'creates the user avoiding race conditions' do
       expect(Suggestion).to receive(:find_or_create_by).and_raise(ActiveRecord::RecordNotUnique)