Which testing framework is used to test ServiceNow Applications?

Test Driven Framework (TDF) is a general software development concept, not a specific ServiceNow testing tool.

JUnit is a testing framework primarily used for Java applications and is not native to ServiceNow application testing.

Selenium is a widely used tool for browser automation and web application testing, but it is external to ServiceNow and not its native testing framework.

The Automated Test Framework (ATF) is a built-in ServiceNow application that allows users to create, run, and manage automated tests for their applications, customizations, and upgrades directly within the platform. It helps ensure that changes do not introduce regressions and that core functionalities continue to work as expected.