Test data in unit test not accessible in trigger

Question

I have a unit test that creates a test account and two test contacts. These test contacts are associated with the test account via Id. The test is for an Account trigger that will then grab all associated contacts with the account and do some logic on them. However, the created contacts don't exist when the trigger is fired.

Test file:

@isTest
private class UpdateContactsOnAccountUpdate_Test {
    @isTest private static void m1()
    {
        account a = new account();
        a.name = 'Test Account';
        insert a;

        contact c = new contact();
        c.FirstName = 'Test';
        c.LastName = 'Test';
        c.Phone = '111-111-1111';
        c.Email = 'test@test.com';
        c.AccountId = a.Id;
        insert c;

        contact c1 = new contact();
        c1.FirstName = 'Test1';
        c1.LastName = 'Test1';
        c1.Phone = '111-111-1111';
        c1.Email = 'test1@test.com';
        c1.AccountId = a.Id;
        insert c1;

        Test.startTest();
        Account account = [SELECT Id, Name FROM Account WHERE Id = :a.Id];
        account.name = 'New Name';
        update account;
        Test.stopTest();
    }
}

Trigger:

trigger UpdateContactsOnAccountUpdate on Account (after update) {
    if(trigger.isupdate)
    {
        account a1 = trigger.new[0];
        List<Contact> ContList = [ select Id, Name from Contact where AccountId = :a1.Id ];
        System.debug('Contlist length: '+ContList.size());
        for(contact c: ContList){
            //logic here
            update ContList;
        }
     }
}

When I run the test, the debug message says "Contlist length: 0" and the for loop is not covered by the test. How do I get the data from my test file to be accessible in the trigger?

Thank you!

Answer 1

Have you tried TestSetup? https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_classes_annotation_testsetup.htm

"Records that are created in a test setup method are available to all test methods in the test class and are rolled back at the end of test class execution."