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Selector Layer
Test Classes

Test Classes

Selector methods can be tested without having to insert or mock any data. Tests will catch out any invalid fields or SOQL queries.

Here is a Selector test class template. You can easily change the SOBJECT_TYPE and EMPTY_LIST variables to cover the generic selector tests.

/* PortalUserSelectorTest.cls */
@IsTest(IsParallel=true)
private class PortalUserSelectorTest {
  public final static SObjectType SOBJECT_TYPE = PortalUser__c.SObjectType;
  public static final List<PortalUser__c> EMPTY_LIST = new List<PortalUser__c>();
  
  /* Generic tests all selectors have */
  @IsTest
  static void shouldReturnRecordSObjectType() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      SOBJECT_TYPE,
      selector.getSObjectType(),
      'Expected object type returned correctly'
    );
  }
 
  @IsTest
  static void shouldReturnQueryFactory() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertNotEquals(
      null,
      selector.getQueryFactory(),
      'Expected a query factory returned'
    );
  }
 
  @IsTest
  static void shouldReturnObjectFieldList() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertNotEquals(
      null,
      selector.getSObjectFieldList(),
      'Expected field list returned'
    );
  }
 
  @IsTest
  static void shouldSetAndGetSObjectFieldListWithRelatedFields() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    selector.setSObjectFieldListWithRelatedFields(new List<String>{ 'test' });
    List<String> result = selector.getSObjectFieldListWithRelatedFields();
    System.assert(!result.isEmpty());
  }
 
  @IsTest
  static void shouldNotGetErrorsOnGettingAdditionalFieldsList() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    selector.getAdditionalSObjectFieldList();
    System.assert(true, 'Expected no errors');
  }
 
  @IsTest
  static void shouldReturnEmptyListWhenSelectByIdHasEmptySetParameterVal() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      EMPTY_LIST,
      selector.selectById(new Set<Id>()),
      'Expected empty list because there is no id values in the Set'
    );
  }
 
  @IsTest
  static void shouldReturnEmptyListWhenSelectByIdSetDoesNotExist() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      EMPTY_LIST,
      selector.selectById(
        new Set<Id>{ fflib_IDGenerator.generate(SOBJECT_TYPE) }
      ),
      'Expected empty list because record id value does not exist'
    );
  }
 
  @IsTest
  static void shouldReturnEmptyListWhenSelectByIdDoesNotExist() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      null,
      selector.selectById(fflib_IDGenerator.generate(SOBJECT_TYPE)),
      'Expected null because record id value does not exist'
    );
  }
 
  @IsTest
  static void shouldReturnEmptyListWhenSelectSObjectsByIdSetDoesNotExist() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      new List<SObject>(),
      selector.selectSObjectsById(
        new Set<Id>{ fflib_IDGenerator.generate(SOBJECT_TYPE) }
      ),
      'Expected empty list because record id value does not exist'
    );
  }
 
  /* Selector specific tests */
  @IsTest
  static void testSelectAll() {
    PortalUserSelector selector = PortalUserSelector.newInstance();
    System.assertEquals(
      EMPTY_LIST,
      selector.selectAll(),
      'Expected empty list because there have been no test records inserted'
    );
  }
}
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