set parameter type on $hostnameitem

add test to fail if hostinterfaceitem is set to fqdn

manifests/agent.pp

@@ -275,7 +275,7 @@
   Stdlib::Ensure::Service $service_ensure         = $zabbix::params::agent_service_ensure,
   Boolean $service_enable                         = $zabbix::params::agent_service_enable,
   $hostname                                       = $zabbix::params::agent_hostname,
-  $hostnameitem                                   = $zabbix::params::agent_hostnameitem,
+  Optional[String[1]] $hostnameitem               = $zabbix::params::agent_hostnameitem,
   $hostmetadata                                   = $zabbix::params::agent_hostmetadata,
   $hostmetadataitem                               = $zabbix::params::agent_hostmetadataitem,
   Optional[Stdlib::Fqdn] $hostinterface           = $zabbix::params::agent_hostinterface,

spec/classes/agent_spec.rb

@@ -154,6 +154,16 @@
         it { is_expected.to contain_file(config_path).with_content %r{^HostInterfaceItem=system.hostname$} }
       end
 
+      context 'configuration file with hostinterfaceitem set to fqdn' do
+        let :params do
+          {
+            hostinterfaceitem: 'zabbix.example.com'
+          }
+        end
+
+        it { is_expected.to compile.and_raise_error(%r{.*}) }
+      end
+
       context 'configuration file with hostinterface' do
         let :params do
           {