System Under Test / Test Target

The System Under Test (SUT) is a term used in software testing to describe the system that is being tested. It could be a single module, an entire application, or even a network of interconnected systems. Testing is performed on the SUT to verify its functionality, performance, and reliability . From a unit testing perspective, the SUT encompasses all the classes in a test that are not predefined pieces of code like stubs or mocks. In other words, it represents the actual software or component under examination during testing.

For instance, if you're testing a specific feature of a web application, that feature becomes the SUT. Similarly, when evaluating the behavior of an entire application, the entire application serves as the SUT. The goal is to ensure that the SUT behaves correctly and meets the specified requirements.

Remember, the SUT is the star of the testing show—it's where all the action happens! 🌟