Apex Test - User email change on UserChangeEvent

Question

I have a trigger on UserChangeEvent that upon Email change event, performs certain operations with the new email address.

Upon email change, Salesforce sends a confirmation email to the user, who then has to verify the change in order for the event to fire. I have successfully manually tested this logic and it works perfect, however, I could not find a way to write a script to test this.

My script successfully creates the user but the email change update never fires (possibly because that cannot be automated)

How can I solve this problem?

@isTest
public class UserEmailChangeTriggerTest {

@isTest static void updateUserTest() {
    
    List<User> user_list = new List<User>();
    Id profileId = [SELECT Id FROM Profile WHERE Name='Standard User'].Id;

    for(Integer i = 1; i <= 2; i++) {
        String email = UserInfo.getUserEmail().substringBefore('@') + '+test' + i + '@' + UserInfo.getUserEmail().substringAfter('@');
        user_list.add(new User(
            FirstName = 'Test',
            LastName = 'User ' + i,
            Email = email,
            Username = email + '.test',
            ProfileId = profileId,
            Alias = 'tUser' + i,
            TimeZoneSidKey = 'America/Los_Angeles',
            EmailEncodingKey = 'UTF-8',
            LocaleSidKey = 'en_US',
            LanguageLocaleKey = 'en_US'
        ));
    }
    System.debug('Users created -');
    System.debug(user_list);

    Test.startTest();

    insert user_list;

    Test.enableChangeDataCapture();

    user_list[1].Email = UserInfo.getUserEmail().substringBefore('@') + '+test1a@' + UserInfo.getUserEmail().substringAfter('@');
    update user_list;

    Test.getEventBus().deliver();

    Test.stopTest();
  }
}

Answer 1

In here a snippet how can be tested:

@isTest
public class UserChangeEventHelperTest {

@TestSetup
static void makeData(){
    Test.enableChangeDataCapture();
    //TestFactory.createUsers(...);
    //In here create the users you want to change email
    Test.getEventBus().deliver();
}

@isTest
public static void updateEmailTest(){
    Test.enableChangeDataCapture();
    User comUser = [SELECT Id, Email FROM User WHERE .. limit 1];
    comUser.Email = '[email protected]';
    update comUser;
    Test.getEventBus().deliver();
    comUser = [SELECT Id, Username FROM User WHERE LegacyUuId__c='testuuid' limit 1];
    system.assertEquals('[email protected]',comUser.Username);
    
}

The error in your code is the position of Test.StartTest(). As the documentation says:

Call the Test.enableChangeDataCapture() method at the beginning of your test method before performing DML operations and calling Test.getEventBus().deliver() or Test.stopTest().

More info in here: https://developer.salesforce.com/docs/atlas.en-us.change_data_capture.meta/change_data_capture/cdc_trigger_testing.htm