Adding a Test Utility Class - Apex Unit Tests

Prerequisites:

• Tutorial #11: Adding Custom Business Logic Using Trigger

In this lesson, you’ll add tests to test the trigger that you created in the previous tutorial. Because you need to create some test data, you’ll add a test utility class that contains methods for test data creation that can be called from any other test class or test method.

1. In the Developer Console, click the Repository tab.
2. In the Setup Entity Type section, click Classes, and then click New.
3. For the class name, enter TestDataFactory and click OK.
4. Delete the auto-generated code and add the following.
   @isTest
   public class TestDataFactory {
   
       public static Invoice_Statement__c createOneInvoiceStatement(
                                                    Boolean withLineItem) { 
           // Create one invoice statement 
       
           Invoice_Statement__c testInvoice = createInvoiceStatement();    
           
           if (withLineItem == true) {
               // Create a merchandise item 
       
               Merchandise__c m = createMerchandiseItem('Orange juice');
               // Create one line item and associate it with the invoice statement.         
       
               AddLineItem(testInvoice, m);
           }                   
           
           return testInvoice;
       }            
       
       // Helper methods 
       
       // 
       
       private static Merchandise__c createMerchandiseItem(String merchName) {
           Merchandise__c m = new Merchandise__c(
               Name=merchName,
               Description__c='Fresh juice',
               Price__c=2,
               Total_Inventory__c=1000);
           insert m;
           return m;
       }
       
       private static Invoice_Statement__c createInvoiceStatement() {        
           Invoice_Statement__c inv = new Invoice_Statement__c(                
               Description__c='Test Invoice');      
           insert inv;
           
           return inv;
       } 
       
       private static Line_Item__c AddLineItem(Invoice_Statement__c inv, 
                                               Merchandise__c m) {
           Line_Item__c lineItem = new Line_Item__c(
                                       Invoice_Statement__c = inv.Id, 
                                       Merchandise__c = m.Id, 
                                       Unit_Price__c = m.Price__c, 
                                       Units_Sold__c = (Double)(10*Math.random()+1));
           insert lineItem;
           
           return lineItem;
       }       
   }

5. Click Save.

Tell Me More...

• This class contains one public method called createOneInvoiceStatement that creates an invoice statement and a merchandise item to be used as test data in test methods in the next lesson. It takes a Boolean argument that indicates whether a line item is to be added to the invoice.
• It also contains three helper methods that are used by createOneInvoiceStatement. These methods are all private and are used only within this class.
• Even though any Apex class can contain public methods for test data creation, this common utility class is defined with the @isTest annotation. The added benefit of using this annotation is that the class won’t count against the 3 MB organization code size limit. The public methods in this can only be called by test code.