Extend tests for delete branch service

spec/services/delete_branch_service_spec.rb

@@ -2,27 +2,40 @@ require 'spec_helper'
 
 describe DeleteBranchService, services: true do
   let(:project) { create(:project) }
+  let(:repository) { project.repository }
   let(:user) { create(:user) }
   let(:service) { described_class.new(project, user) }
 
   describe '#execute' do
-    let(:result) { service.execute('feature') }
-
     context 'when user has access to push to repository' do
       before do
         project.team << [user, :developer]
       end
 
       it 'removes the branch' do
+        expect(branch_exists?('feature')).to be true
+
+        result = service.execute('feature')
+
         expect(result[:status]).to eq :success
+        expect(branch_exists?('feature')).to be false
       end
     end
 
     context 'when user does not have access to push to repository' do
       it 'does not remove branch' do
+        expect(branch_exists?('feature')).to be true
+
+        result = service.execute('feature')
+
         expect(result[:status]).to eq :error
         expect(result[:message]).to eq 'You dont have push access to repo'
+        expect(branch_exists?('feature')).to be true
       end
     end
   end
+
+  def branch_exists?(branch_name)
+    repository.ref_exists?("refs/heads/#{branch_name}")
+  end
 end