Test Class To Cover Email Message trigger in Salesforce

Sample Test class code:-

//    Create case with test data

         Case Cas= new Case();
         Cas.Subject= 'testsubject';
         Cas.recordtypeid=casRecordTypeId;
         Cas.AccountId=acc.id; 
         Cas.ContactId=con.id;
         insert Cas;
 
//      Below data covers if you trigger logic  for outgoing email 
//     That will be decided based on flag Incoming (default is false)

 EmailMessage outGoingMail= new EmailMessage();
         outGoingMail.fromaddress='test@test.com';
         outGoingMail.toAddress = con1.Email;
         outGoingMail.subject = 'Opt Out Test Message';
         outGoingMail.TextBody= 'This is the message body BR-Interno.';
         outGoingMail.parentid=Cas.id;
         insert outGoingMail;          
          
  //*********** incoming email message*************
//    Incoming flag tru makes this as incoming email.          
 //    you can update fromaddress and toAddress according to your logic

         EmailMessage incomingMail = new EmailMessage();
         incomingMail .fromaddress=test@email.com;
         incomingMail .toAddress = test@test.com;
         incomingMail .subject = ' Test Message';
         incomingMail .TextBody= 'This is the message body ';
         incomingMail .parentid=Cas.id;
         incomingMail .incoming=true;
         insert incomingMail ;