TomLocalFileSystem constructor
watchEachDirectory chooses how watch is recursive: one watch per
directory (TomDirectoryWatches) or the platform's own recursive
watch. It is true on Linux, where Directory.watch is not recursive,
and false elsewhere; a test sets it to run the Linux way on any host.
Implementation
TomLocalFileSystem(String root, {bool? watchEachDirectory})
: rootPath = p.normalize(p.absolute(root)),
_watchEachDirectory = watchEachDirectory ?? Platform.isLinux,
super(Uri.directory(p.normalize(p.absolute(root))));