We all know the .NET Framework APIs for dealing with the file system are not designed with testability in mind. Also, I wasn't happy with the existing libraries for providing an abstraction for such things. I wanted one that was:

• Modern - Included the Enumerate* methods for example.
• Interface based - Using Abstract base classes as the abstraction is blech.
• Easy to port to - So it had to follow the existing APIs closely.

Rothko is this library. It provides abstractions for:

• File system.
• Registry
• Environment.

The starting point for Rothko is the OperatingSystemFacade class. From there you can get to the other abstractions.

• IFileSystem
• IEnvironment
• IRegistry

The goal is to use this in GitHub for Windows as well as any other applications where testability is important.

A secondary goal is to make it very easy to port code using the core .NET Framework APIs to port over to Rothko. The interfaces map closely to the .NET Framework's, except in a few places where I wouldn't be able to live with myself if I didn't modernize the library. For example, I updated methods that return arrays to return IEnumerable (or derived interface) instead.

Once these low level abstractions are implemented, I plan to add a set of Facade classes that provide a more usable API that we all wished had been there all along. These Facade classes will simply delegate to the lower-level abstractions.