1. mscorlib
   Fakeable types via Typemock (below) or experience a TypemockException.
2. Gist.
   http://bit.ly/2ieJbl1
3. Scenario.

We need to make a small update within a much larger set of functionality:

1. How do we test that change?
   Test the smallest slice of functionality as possible.
2. How do we make that change?
   Write a test that verifies the behavior or confirms the bug, then make updates.

http://www.typemock.com/mscorlib-types

Typemock Isolator supports the following types within mscorlib:

• System
  • DateTime
  • Environment
• System.IO
  • File
  • Directory
  • FileStream
• System.Security.Cryptography.X509Certificates
  • X509Certificate

TypeMock.TypeMockException : *** Exception throw while recording calls. Please check:

• Are you trying to fake a field instead of a property? try to set field or use Isolate.Invoke.StaticConstructor
• Are you are trying to fake an unsupported mscorlib method? See supported types here: http://www.typemock.com/mscorlib-types InnerException ----> System.Reflection.TargetInvocationException : Exception has been thrown by the target of an invocation. ----> System.ArgumentNullException : String reference not set to an instance of a String. Parameter name: s