add acceptance test to verify default values

spec/acceptance/init_spec.rb

@@ -0,0 +1,34 @@
+require 'spec_helper_acceptance'
+
+describe 'nginx class' do
+  context 'default parameters' do
+    # Using puppet_apply as a helper
+    it 'works idempotently with no errors' do
+      pp = 'include nginx'
+
+      # Run it twice and test for idempotency
+      apply_manifest(pp, catch_failures: true)
+      apply_manifest(pp, catch_changes: true)
+    end
+
+    # do some basic checks
+    pkg = case fact('os.family')
+          when 'Archlinux'
+            'nginx-mainline'
+          else
+            'nginx'
+          end
+    describe package(pkg) do
+      it { is_expected.to be_installed }
+    end
+
+    describe service('nginx') do
+      it { is_expected.to be_running }
+      it { is_expected.to be_enabled }
+    end
+
+    describe port(80) do
+      it { is_expected.to be_listening }
+    end
+  end
+end