MockK

Mockito is a mocking framework that tastes really good. It lets you write beautiful tests with a clean & simple API. Mockito doesn’t give you hangover because the tests are very readable and they produce clean verification errors. Read more about features & motivations. Top 10 Java library across all libraries, not only the testing tools. In late 2013 there was an analysis made of 30.000 GitHub projects. Although Mockito reached number 9 in the main report, mockito-core and mockito-all are the same tool and therefore the factual position of Mockito is number 4, surpassing famous tools like Guava or Spring. Treat this study as an indicator of a big impact that Mockito makes every day on unit tests written in Java.

JustMock allows you to easily isolate your testing scenario and lets you focus on the logic you want to verify. It integrates seamlessly with your favorite unit testing framework and makes unit testing and mocking simple and fast. Mock everything like non-virtual methods, sealed classes, static methods and classes, as well as non-public members and types everywhere even members of MsCorLib. The perfect tool for unit testing your .NET code whether you're dealing with complex and hard to maintain legacy code or code written with best practices in mind. From finding what arguments your mock object is called with to why it’s not called or why it’s called repeatedly, the JustMock Debug Window helps you find the answers you are looking for while debugging your unit tests. JustMock allows you to receive critical feedback about the completeness and thoroughness of your unit tests—an absolute must for any organization that strives for high-quality code.