1 files changed, 89 insertions, 0 deletions
diff --git a/spec/models/concerns/cross_database_modification_spec.rb b/spec/models/concerns/cross_database_modification_spec.rb
new file mode 100644
index 00000000000..72544536953
--- /dev/null
+++ b/spec/models/concerns/cross_database_modification_spec.rb
@@ -0,0 +1,89 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe CrossDatabaseModification do
+  describe '.transaction' do
+    context 'feature flag disabled' do
+      before do
+        stub_feature_flags(track_gitlab_schema_in_current_transaction: false)
+      end
+
+      it 'does not add to gitlab_transactions_stack' do
+        ApplicationRecord.transaction do
+          expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+          Project.first
+        end
+
+        expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+      end
+    end
+
+    context 'feature flag is not yet setup' do
+      before do
+        allow(Feature::FlipperFeature).to receive(:table_exists?).and_raise(ActiveRecord::NoDatabaseError)
+      end
+
+      it 'does not add to gitlab_transactions_stack' do
+        ApplicationRecord.transaction do
+          expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+          Project.first
+        end
+
+        expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+      end
+    end
+
+    it 'adds the current gitlab schema to gitlab_transactions_stack', :aggregate_failures do
+      ApplicationRecord.transaction do
+        expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_main)
+
+        Project.first
+      end
+
+      expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+      Ci::ApplicationRecord.transaction do
+        expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_ci)
+
+        Project.first
+      end
+
+      expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+      Project.transaction do
+        expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_main)
+
+        Project.first
+      end
+
+      expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+      Ci::Pipeline.transaction do
+        expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_ci)
+
+        Project.first
+      end
+
+      expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+
+      ApplicationRecord.transaction do
+        expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_main)
+
+        Ci::Pipeline.transaction do
+          expect(ApplicationRecord.gitlab_transactions_stack).to contain_exactly(:gitlab_main, :gitlab_ci)
+
+          Project.first
+        end
+      end
+
+      expect(ApplicationRecord.gitlab_transactions_stack).to be_empty
+    end
+
+    it 'yields' do
+      expect { |block| ApplicationRecord.transaction(&block) }.to yield_control
+    end
+  end
+end