NewFakeEnv returns a new FakeEnv with no values in Envs.

NewFakeFS returns a FakeFS with no files.

RealEnv returns an Env implementation that uses os.Getenv every time Get is called.

RealFS returns an FS object that interacts with the real local filesystem.

FakeEnv is an Env implementation that stores the environment in a map.

FakeFileNotFound is the error returned by FakeFS when a requested file isn't found.

FakeFS is an in-memory FS implementation.

Env is an interface to a set of environment variables.

FS is the interface to a file system.