HowDoesItWork

How does it work?

Interfaces

No magic is happening when mocking interfaces and virtual methods. Source generators will generate an implementation of your contract and will fill it in with the logic for a MockMe mock.

Concrete / Sealed Classes

For most scenarios involving concrete classes, the work that MockMe is doing is actually pretty simple. MockMe uses a different library called Harmony which is made for patching methods without modifying dlls.

The patching process involves creating a new method at runtime using intermediate language instructions, and then modifying the memory address of the original method's pointer to point to the newly created method.

Generics

Generic methods of concrete classes are tricky / sometimes impossible to patch. In this scenario, MockMe is actually instrumenting your dlls post-build using an amazing library called Mono.Cecil.

This means that, when mocking generic methods or classes, MockMe is modifying your dll. However, the changes are minimal, and it will only modify the dlls that are in the bin folder of the test project. This means that the dll living in the publish folder or in the bin folder of your 'src' project will be unchanged. This is a similar process to other popular dll instrumentation tools such as Coverlet.