Improved BaseSyncService specs

app/services/geo/base_sync_service.rb

@@ -31,6 +31,10 @@ module Geo
 
     private
 
+    def sync_repository
+      raise NotImplementedError, 'This class should implement sync_repository method'
+    end
+
     def registry
       @registry ||= Geo::ProjectRegistry.find_or_initialize_by(project_id: project.id)
     end

spec/services/geo/base_sync_service_spec.rb

 require 'spec_helper'
 
 describe Geo::BaseSyncService, services: true do
-  let(:project) { double('project')}
+  let(:project) { build('project')}
   subject { described_class.new(project) }
 
+  describe '#execute' do
+    context 'when can acquire exclusive lease' do
+      before do
+        allow_any_instance_of(Gitlab::ExclusiveLease).to receive(:try_obtain) { 12345 }
+      end
+
+      it 'executes the synchronization' do
+        expect(subject).to receive(:sync_repository)
+
+        subject.execute
+      end
+    end
+
+    context 'when exclusive lease is not acquired' do
+      before do
+        allow_any_instance_of(Gitlab::ExclusiveLease).to receive(:try_obtain) { nil }
+      end
+
+      it 'is does not execute synchronization' do
+        expect(subject).not_to receive(:sync_repository)
+
+        subject.execute
+      end
+    end
+  end
+
+  describe '#lease_key' do
+    it 'returns a key in the correct pattern' do
+      described_class.type = :test
+      allow(project).to receive(:id) { 999 }
+
+      expect(subject.lease_key).to eq('geo_sync_service:test:999')
+    end
+  end
+
   describe '#primary_ssh_path_prefix' do
     let!(:primary_node) { create(:geo_node, :primary, host: 'primary-geo-node') }