INSSET Salesforce Programmer Training

Merchandise Trigger

trigger HandleProductPriceChange on Merchandise__c (after update) {

    List<Line_Item__c> openLineItems =
        [SELECT j.Unit_Price__c, j.Merchandise__r.Price__c
         FROM Line_Item__c j
         WHERE j.Invoice__r.Status__c = 'Negotiating'
         AND j.Merchandise__r.id IN :Trigger.new
         FOR UPDATE];

    for (Line_Item__c li: openLineItems) {
        if ( li.Merchandise__r.Price__c < li.Unit_Price__c ){
        li.Unit_Price__c = li.Merchandise__r.Price__c;
        }
    }
    
    //moyens d'évoquer modification base de données  
    // update openLineItems;
    // Database.update(openLineItems);
    //failures in the above examples throw DMLException; 
    
    List<Database.Saveresult> srs = Database.update(openLineItems,false);
    
    for (Database.SaveResult sr : srs) {
    	
    	if (!sr.isSuccess()){
    		System.debug('The line item record ' +sr.getId()+ ' did not update successfully ' +sr.getErrors());
    	}
    	
    }
}

Simple Unit Test Example

/*
The following represents two separate classes in Apex. You must create them both. 
You cannot add these to the same class.
*/
public class MathHelper{
    
    public static Integer add(Integer a, Integer b){
    	return a+b;    
    }

}

@istest
public class MathHelperTest{
    
    @istest
    public static void testAddTwoNumbers(){
    	Integer val1 = 2;
        Integer val2 = 3; 
        
        Integer product = MathHelper.add(val1,val2);
        
        System.assert(product==5, 'the product does not equal 5');
        System.assertEquals(5, product);
        System.assertNotEquals(6, product); 

        //code to show that any changes written to the DB are not committed during test execution
        Merchandise__c m = new Merchandise__c(name='Père Noël',Price__c=10,Quantity__c=100);
        insert m; 
        
        Merchandise__c merchandiseFromDB = [SELECT name from Merchandise__c where name = 'Père Noël']; 
        System.debug(merchandiseFromDB); 
        
        
    }
    

}