1 files changed, 35 insertions, 0 deletions
diff --git a/spec/lib/gitlab/database/postgres_sequences_spec.rb b/spec/lib/gitlab/database/postgres_sequences_spec.rb
new file mode 100644
index 00000000000..2373edaea18
--- /dev/null
+++ b/spec/lib/gitlab/database/postgres_sequences_spec.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::PostgresSequence, type: :model, feature_category: :database do
+  # PostgresSequence does not `behaves_like 'a postgres model'` because it does not correspond 1-1 with a single entry
+  # in pg_class
+  let(:schema) { ActiveRecord::Base.connection.current_schema }
+  let(:table_name) { '_test_table' }
+  let(:table_name_without_sequence) { '_test_table_without_sequence' }
+
+  before do
+    ActiveRecord::Base.connection.execute(<<~SQL)
+      CREATE TABLE #{table_name} (
+        id bigserial PRIMARY KEY NOT NULL
+      );
+
+      CREATE TABLE #{table_name_without_sequence} (
+        id bigint PRIMARY KEY NOT NULL
+      );
+    SQL
+  end
+
+  describe '#by_table_name' do
+    context 'when table does not have a sequence' do
+      it 'returns an empty collection' do
+        expect(described_class.by_table_name(table_name_without_sequence)).to be_empty
+      end
+    end
+
+    it 'returns the sequence for a given table' do
+      expect(described_class.by_table_name(table_name).first[:table_name]).to eq(table_name)
+    end
+  end
+end