- Tags:: [[Software Testing]] - Date Created: [[2020-09-12]] - Test doubles are simpler versions of existing systems and services that are sufficiently realistic as to be able to replace the original component for testing purposes. - Test doubles are useful because they can reduce the complexity or financial costs of reproducing an application/environment while allowing developers and testers to verify the quality of their work. - If you are willing to put the time into creating a test double, you can drastically reduce the amount of resources you need to set up an environment and isolate components. Reducing variables in your test allows you to more quickly determine where performance bottlenecks lie. - Test doubles vary in scope and complexity of their implementation: - [[Stubs]] - [[Mocks]] - [[Service virtualization]] - [[Test Double Tools]]