Fix MemoryFileSystem to treat an empty path as non-existent (#213)

* Fix MemoryFileSystem to treat an empty path as non-existent

`_MemoryFileSystem.findNode` returns `reference?.directory` if given
the root path or an empty path.  However, an empty path should
be treated as non-existent, not as a directory.  Instead explicitly
return `null` as a special case when given an empty path.

Partially addresses https://github.com/google/file.dart/issues/198.

* Make _MemoryFileSystem._current nullable
3 files changed
tree: d52e132742a1a07825b04b2f7d792c8203dfaf9e
  1. .github/
  2. packages/
  3. .gitignore
  4. README.md
README.md

Dart

A monorepo for the package:file and package:file_testing packages.

PackageDescriptionPublished Version
fileA pluggable, mockable file system abstraction for Dart.pub package
file_testingTesting utilities for package:file.pub package