global with sharing class JunkQueueBatchJob implements Database.Batchable<sObject>
{
    global Database.QueryLocator start(Database.BatchableContext BC)
    {   
        String query = 'select id from case where owner.Name = \'To Be Deleted\' AND createddate < LAST_N_MONTHS:5 ORDER BY Createddate DESC ';

        return Database.getQueryLocator(query);
    }
    global void execute(Database.BatchableContext BC, List<Case> scope)
    {
        delete scope;
    }
    global void finish(Database.BatchableContext BC) {
    }
    
}

//excerpt from test method
list<Case> mktcses = new list<Case>();
        Id mktcse = Schema.SObjectType.Case.getRecordTypeInfosByName().get('Marketing Component').getRecordTypeId();
        
        Case cse1 = new Case();
        cse1.RecordTypeId = mktcse;
        cse1.AccountId = acctObj.Id;
        cse1.ContactId = conObj.Id;
        cse1.Status = 'In Progress';
        cse1.Description = 'Test';
        cse1.Subject = 'Dental Equipment Broadcast';
        cse1.Materials_Due_Date__c = date.today().addDays(60);
        
        mktcses.add(cse1); 

Case cse2 = new Case();
        cse2.RecordTypeId = mktcse;
        cse2.AccountId = acctObj.Id;
        cse2.ContactId = conObj.Id;
        cse2.Status = 'In Progress';
        cse2.Description = 'Test';
        cse2.Subject = 'Dental Webinar';
        cse2.Materials_Due_Date__c = date.today().addDays(60);
        cse2.CreatedDate = date.today().addMonths(-6); 
        
        system.debug('createddate*****'+cse2.CreatedDate);
   
        mktcses.add(cse2);
        
        insert mktcses;
        
            test.startTest(); 
            
            id sysid;
            
            For(Group grp:[Select id, name, owner.name from Group where type ='Queue' AND Name = 'To Be Deleted']) {

                sysid = grp.id;
            }
             cse2.OwnerId = sysid;
            		update cse2;
            system.debug('cse2 owner name_____'+sysid);
            
 //JunkQueueBatchJob is chained with batch class called from scheduler
            Den_Marketing_Scheduler dms = new Den_Marketing_Scheduler();
            String sch = '0 0 23 * * ?'; 
            system.schedule('denmailer', sch, dms);
            
            system.debug('Cases after Deletion*****'+mktcses.size());
            //should return with 1 but is returning 2 (cse2 should have been deleted)

            test.stopTest();

    }

 //system.assertEquals(1, mktcses.size());