Mock or isolation frameworks are the bread and butter of advanced unit testing scenarios. There are many to choose from, and that’s a great thing:
The previous edition of this book contained the following tools, which I’ve removed due to being out of date or relevance:
Here’s a short description of each framework.
Moq is an open source isolation framework and has an API that tries to be both simple to learn and easy to use. The API was one of the first to follow the arrange-act-assert style (as opposed to the record-and-replay model in older frameworks) and relies heavily on .NET 3.5 and 4 features, ...