Architecting Modern Java EE Applications

Simulating external concerns

System test scenarios use external systems in the same way as in production. However, similar to mock objects in unit and component tests, system tests simulate and mock away external systems. In this way, potential issues that the application isn't responsible for are eliminated. System tests run in dedicated environments, for example, provided by container orchestration frameworks. The test object is the sole application, deployed, executed and configured in the same way as in production.

Simulated external systems are configured to provide the expected behavior once accessed by the application. Similar to a mock object, they verify correct communication depending on the use case.

For the majority of use cases, ...