Acceptance Test Library (ATL) is used for validation testing in Microsoft Dynamics 365 Finance and Operations One version. It has been available since May 2019 in PU26, application version 10.0.2.
So, are you wondering how to leverage classes that are used internally by Microsoft to test the code? This is it. You can skip UI and directly debug the code – ATL is the tool. ATL is suggested to be best used for data setup testing, as well as for validation testing of integration and components. In some scenarios, it could be used for unit tests.
Let's now explore what this library offers us, and how we benefit:
- It lets you create consistent test data.
- It increases the readability of test code.
- It provides improved discoverability of the methods that are used to create test data.
- It hides the complexity of setting up prerequisites.
- It supports the high performance of test cases.
The internal mechanics need to be decoded in order to break the classes that are used:
- Navigation: Discover entities and test data methods in a familiar hierarchy.
- Test data methods: These methods are used to set up test data.
- Entities: Represent data and associated behavior that is perceived as a single unit.
- Creators: Allow you to create specific test data by providing fluent application programming interfaces (APIs).
- Commands: Run business operations.
- Queries: Find entities.
- Specifications: Describe the entities that are expected at the end of the test.
So, if you are keen to make a test repeatable without going through several regressions, then ATL is the way to go.