Stub

Stub is a specialized form of a test double used primarily in software testing to simulate the behavior of a component. It is a skeletal or partial implementation of a software component that provides predefined responses to calls made to it during testing. Stubs are particularly useful when testing higher-level components that depend on lower-level services, which may not yet be developed or available. By using stubs, developers can isolate the unit under test and focus on testing its functionality without being concerned about the behavior or availability of its dependencies.

A stub typically replaces a called component and is designed to mimic its behavior to a limited extent. This allows the developer to test components in isolation by providing controlled responses and ensuring that the code being tested behaves correctly with these simulated interactions. Stubs are often used in unit testing scenarios where the goal is to test the logic of a particular module or function independently of other components. By providing predefined outputs and not executing any actual logic, stubs help in identifying issues within the unit under test without interference from other parts of the system.