Good evening all,

As of 8 March 2019, the selected code sample no longer works. I used it as a model to write my own code, but there was a 25% section that would not be covered by code, regardless of whether I was using my code or the code provided by several other users. I found that commenting out the code allowed the Trailhead to pass.

Here is my code, with the selected 25% commented out:

AddPrimaryContact:

public class AddPrimaryContact implements Queueable {
    private Contact contact;
    private String state;
    
    public AddPrimaryContact(Contact c, String st) {
        this.contact = c;
        this.state = st;
    }
    
    public void execute(QueueableContext context) {
        List<Account> accountList = [SELECT ID, Name,
                                     (Select id, FirstName, LastName from Contacts)
                                     FROM ACCOUNT WHERE BillingState = :state
                                     LIMIT 200];
        
        List<Contact> contactList = new List<Contact>();
        
        for(Account acc : accountList) {
//            Contact newContact = contact.clone(false, false, false, false);
//            newContact.AccountID = acc.Id;
//            contactList.add(newContact);
        }
        
        insert contactList;    
    }
    
}

AddPrimaryContactTest:

@isTest

public class AddPrimaryContactTest {
    
    @isTest static void apctest() {
        
        List<Account> testList = new List<Account>();
        
        for(Integer i; i < 50; i++) {
            Account cal = new Account();
            cal.Name = 'California ' + i;
            cal.BillingState = 'CA';
            testList.add(cal);

            Account ny = new Account();
            ny.Name = 'New York ' + i;
            ny.BillingState = 'NY';
            testList.add(ny);
        }

        insert testList;

        contact testContact = new Contact();
        testContact.FirstName = 'Evelyn';
        testContact.LastName = 'Maguire';
        insert testContact;
        String testState = 'CA';

        AddPrimaryContact testAPC = new AddPrimaryContact(testContact, testState);

        Test.startTest();
            System.enqueueJob(testAPC);
        Test.stopTest();   
    }
}