Apex Controller - How To Access Read-Only Variable In Test Class

Question

I've been searching for hours to write a test class for the Controller.

Scenario: All Visualforce Page will use this controller to export a CSV/Excel template from List View. This Controller has written by another Dev that stopped working and I'm quite new to it.

Here Is The Code For Controller:

public with sharing class ExportTemplateController {
    
    public String xlsHeader{
        get{
            String strHeader = '';
            strHeader += '<?xml version="1.0"?>';
            strHeader += '<?mso-application progid="Excel.Sheet"?>';
            return strHeader;
        }
    }
    
    public String filterNameData{
        get{
            String selectedFilterId = this.controller.getFilterId();
            return selectedFilterId;
        }
    }
    
    ApexPages.StandardSetController controller;    
    public ExportCSVController(ApexPages.StandardSetController controller) {
        
        this.controller = controller;   
        if (controller.getResultSize() < 2000 ) {
            controller.setPageSize(controller.getResultSize());
        } else {
            controller.setPageSize(2000);
        }
   }

My understanding of the code: It is written so that any Standard Controller (Account, Lead, Opportunity) can use it. The code also retrieved a filter name/ filter Id of List View. After it has the filter Id, it will check the size (how many records that List View has).

My test class:

@isTest private class ExportTemplateControllerTest {

@isTest
private static void ExportTemplateTest() {

    //Try insert a list of accounts to use Account Controller

    List<Account> testAccs = new List<Account>();
    for (Integer i = 0; i < 200; i++) {
        Account a = new Account(Name='TestAccount' + i);
        testAccs.add(a);
    }
    insert testAccs;
    
    Test.startTest();
    PageReference pageRef = Page.OpenAccountPage;
    Test.setCurrentPage(pageRef);
    ApexPages.StandardSetController stdSetController = new ApexPages.StandardSetController(testAccs);
    stdSetController.setSelected(testAccs);
    ExportCSVController ext = new ExportCSVController(stdSetController);
    System.assertEquals(200, 200);
    Test.stopTest();
}

}

I read a very good explanation Apex Test - Instantiate new Controller but I still don't know how to figure out how to access those 2 public strings xlsHeader & filterNameData

Thank you guys so much,

Pam.

Answer 1

The lines not being covered are properties referenced by the VF page

public String xlsHeader{
    get{
        String strHeader = '';
        strHeader += '<?xml version="1.0"?>';
        strHeader += '<?mso-application progid="Excel.Sheet"?>';
        return strHeader;
    }
}

public String filterNameData{
    get{
        String selectedFilterId = this.controller.getFilterId();
        return selectedFilterId;
    }
}

as such, you need to simulate access to them as if the VF page were requesting their values.

after this line in your testmethod:

stdSetController.setSelected(testAccs);
stdSetController.setFilterId('someFilterId');  // init the filterId 
ExportCSVController ext = new ExportCSVController(stdSetController);

you will do

Assert.areEqual('<?xml version="1.0"?><?mso-application progid="Excel.Sheet"?>',ext.xlsHeader,
               's/s header sb as expected'); 

and

Assert.areEqual('someFilterId',ext.filterSomeData,'stdSetController filterId sb returned');

These lines simulate the VF page fetching the variable's getters

Lastly, this line in your testmethod:

 System.assertEquals(200, 200);

is a tautology and adds no value, it should be

 Assert.areEqual(200,ext.getPageSize(),
                'pg size sb # of records in set controller when fewer than 2000 recs');
  

Note best practice of always using a string message to explain the assert.

P.S.

If this is all the controller does, you dont need to insert the Accounts. The set Controller accepts a list of Sobjects

List<Account> testAccs = new List<Account>();
for (Integer i = 0; i < 200; i++) {
    Account a = new Account(Name='TestAccount' + i);
    testAccs.add(a);
}
// insert testAccs; - not required unless your controller is querying or DML'ing these

This makes running the test faster and you can thus easily test the code path for the result size of > 2000 without having to insert 2000 accounts and potentially running into Limits issues