afv-library/skills/generating-apex-test/references/test-data-factory.md

TestDataFactory Patterns

For the base class template, see assets/test-data-factory-template.cls.

Design Rules

1. Always accept a doInsert flag — lets callers modify records before insert
2. Append loop index to all fields that participate in matching rules — prevents DUPLICATES_DETECTED errors from active Duplicate Rules
3. Single-record methods delegate to bulk — e.g., createAccount(doInsert) calls createAccounts(1, doInsert)[0]
4. Return created records — enables chaining and further manipulation
5. Set all required fields — include fields enforced by validation rules, not just schema-required fields

Field Override Pattern

Allow callers to override default values without creating new factory methods:

public static Account createAccount(Map<String, Object> fieldOverrides, Boolean doInsert) {
    Account acc = new Account(
        Name = 'Test Account',
        Industry = 'Technology'
    );
    for (String fieldName : fieldOverrides.keySet()) {
        acc.put(fieldName, fieldOverrides.get(fieldName));
    }
    if (doInsert) insert acc;
    return acc;
}

// Usage:
Account acc = TestDataFactory.createAccount(new Map<String, Object>{
    'Name' => 'Custom Name',
    'Industry' => 'Healthcare'
}, true);

Record Type Support

public static Account createAccountByRecordType(String recordTypeName, Boolean doInsert) {
    Id recordTypeId = Schema.SObjectType.Account
        .getRecordTypeInfosByDeveloperName()
        .get(recordTypeName)
        .getRecordTypeId();

    Account acc = new Account(
        Name = 'Test Account',
        RecordTypeId = recordTypeId
    );
    if (doInsert) insert acc;
    return acc;
}

Handling Duplicate Rules

When unique field values alone are not sufficient, use Database.insert() with a DuplicateRuleHeader:

public static List<Account> createAccountsAllowDuplicates(Integer count, Boolean doInsert) {
    List<Account> accounts = new List<Account>();
    for (Integer i = 0; i < count; i++) {
        accounts.add(new Account(
            Name = 'Test Account ' + i,
            Phone = '555-000-' + String.valueOf(i).leftPad(4, '0')
        ));
    }
    if (doInsert) {
        Database.DMLOptions dml = new Database.DMLOptions();
        dml.DuplicateRuleHeader.allowSave = true;
        Database.insert(accounts, dml);
    }
    return accounts;
}