How Moles Isolation framework is implemented?
- by Buu Nguyen
Moles is an isolation framework created by Microsoft. A cool feature of Moles is that it can "mock" static/non-virtual methods and sealed classes (which is not possible with frameworks like Moq). Below is the quick demonstration of what Moles can do:
Assert.AreNotEqual(new DateTime(2012, 1, 1), DateTime.Now);
// MDateTime is part of Moles; the below will "override" DateTime.Now's behavior
MDateTime.NowGet = () => new DateTime(2012, 1, 1);
Assert.AreEqual(new DateTime(2012, 1, 1), DateTime.Now);
Seems like Moles is able to modify the CIL body of things like DateTime.Now at runtime. Since Moles isn't open-source, I'm curious to know which mechanism Moles uses in order to modify methods' CIL at runtime. Can anyone shed any light?