I am having issues testing the one trigger I have. My problem is that in my test class when I insert a QuoteLineItem or OpportunityLineItem object the Product2Id fields are NULL. Well that's a problem because the trigger I developed uses that as a key between the two fields.
Here's the code for example.

trigger MultTransfer on QuoteLineItem (before insert) {
	//trigger for linking multiplier from OpportunityLineItem to QuoteLineItem
    //public Map<String, QuoteLineItem> quoteMap = new Map<String, QuoteLineItem>();
    public Map<Id, QuoteLineItem> quoteMap = new Map<Id, QuoteLineItem>();
    String quoteID,oppID;
    for(QuoteLineItem qli: Trigger.new){
    	//dumping all the QuoteLineItems into the map, also grabbing their quote ID
        quoteMap.put(qli.Product2Id,qli);
        quoteID=qli.QuoteId;
    }
    //creating a Quote object to find the OpportunityId
    public Quote q =[SELECT OpportunityId FROM Quote WHERE Id=:quoteID];
    oppID=q.OpportunityId;
    public OpportunityLineItem[] oli = [SELECT Product2Id, Multiplier__c, UnitPrice FROM OpportunityLineItem WHERE OpportunityId=:oppID];
    Integer i=0;
    for(i=0;i<oli.size();i++){
        if(quoteMap.containsKey(oli[i].Product2Id)){
        	if(quoteMap.get(oli[i].Product2Id).UnitPrice==oli[i].UnitPrice){//Extra hoop incase multiple quotes with different multipliers
        		quoteMap.get(oli[i].Product2Id).QuoteMultiplier__c=oli[i].Multiplier__c;//setting the new quote multiplier
        		try{
        			update quoteMap.get(oli[i].Product2Id);
        		}catch(Exception e){
        			//You done goofed
        		}
        	}
        }
    }
}

 

@istest(SeeAllData=true)
public class TestMultTransfer{
    static testmethod void test(){
        String opportunityName = 'My Opportunity';
        String standardPriceBookId = '';

        PriceBook2 pb2Standard = [select Id from Pricebook2 where isStandard=true];
        standardPriceBookId = pb2Standard.Id;
        
        Opportunity o = new Opportunity(AccountId=null, Name=opportunityName, 
        StageName='Prospecting', CloseDate=Date.today());

        insert o;
        Opportunity opp = [SELECT Name FROM Opportunity WHERE Id = :o.Id];
        opp.Name=opportunityName;
        update opp;
        System.assertEquals(opportunityName, opp.Name);

        Product2 p2 = new Product2(Name='Test Product',isActive=true);
        insert p2;
        Product2 p2ex = [SELECT Name FROM Product2 WHERE Id = :p2.Id];
        System.assertEquals('Test Product', p2ex.Name);

        PricebookEntry pbe = new PricebookEntry(Pricebook2Id=standardPriceBookId, UnitPrice=322, isActive=true, Product2=p2, Product2Id=p2.Id);
        insert pbe;
        PricebookEntry pbeex = [SELECT Pricebook2Id FROM PricebookEntry WHERE Id = :pbe.Id];
        System.assertEquals(standardPriceBookId, pbeex.Pricebook2Id);

        OpportunityLineItem oli = new OpportunityLineItem(PriceBookEntryId=pbe.Id, OpportunityId=o.Id, 
        	Quantity=1, Opportunity=o, Multiplier__c=0.50, UnitPrice=pbe.UnitPrice, PricebookEntry=pbe);
        insert oli;
        //system.assertEquals(p2.Id,oli.Product2Id);
        OpportunityLineItem oliex = [SELECT PriceBookEntryId FROM OpportunityLineItem WHERE Id = :oli.Id];
        System.assertEquals(pbe.Id, oliex.PriceBookEntryId);
        
        Quote q = new Quote(
        	Name='MyQuote',
        	opportunityid=o.id, 
        	pricebook2id=pb2Standard.Id);
 		insert q;
        
        QuoteLineItem qli = new QuoteLineItem(
        	PricebookEntry=pbe, quoteid=q.id, PricebookEntryId=pbe.Id, 
        	Quantity=oli.Quantity, UnitPrice=oli.UnitPrice, QuoteMultiplier__c=1.00);
        
        insert qli;
        system.assertEquals(p2.Id,qli.Product2Id);
        //System.assertEquals(oli.Multiplier__c, qli.QuoteMultiplier__c);
    }
}