I'm trying to make a custom controller, but can't get the testMethod to work. When running test I get the following error:

System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [OpportunityId]: [OpportunityId]

 I've tried different things with no luck. 

My controller code  with testMethod is:

public class newContactCont {
    public static testMethod void testNewContactCont() {
 
        newContactCont ctrl = new newContactCont();
        
        Account account = ctrl.getAccount();
        Contact contact = ctrl.getContact();
        Opportunity opp = ctrl.getOpportunity();
        OpportunityContactRole role = ctrl.getRole();

        contact.lastname = 'TestLastName';
        role = new OpportunityContactRole(OpportunityId=opp.Id);
        PageReference save = ctrl.save();

    }
    
    Account account;
    Contact contact;
    Opportunity opportunity;
    OpportunityContactRole role;
    
    public Account getAccount() {
        if(account == null) account = new Account();
        return account;
    } 
    
    public Contact getContact() {
        if(contact == null) contact = new Contact();
        return contact;
    }
    
    public Opportunity getOpportunity() {
        if(opportunity == null) opportunity = new Opportunity();
        return opportunity;
    }
    
    public OpportunityContactRole getRole() {
        if(role == null) role = new OpportunityContactRole();
        return role;
    }
    
    public PageReference cancel() {
        PageReference opportunityPage = new ApexPages.StandardController(opportunity).view();
        opportunityPage.setRedirect(true);
        return opportunityPage;
    }
    
    public PageReference save() {

        insert contact;

        role.contactId = contact.id;
        insert role;
        
        PageReference opptyPage = new ApexPages.StandardController(contact).view();
        opptyPage.setRedirect(true);
        
        return opptyPage;
    }

}

 I got the same error for LastName in Contact the first time I tried it and solved it by adding: 

 contact.lastname = 'TestLastName';

I can't however find a solution for the OpportunityId in Role.

Anyone got any suggestions?