Windows FileWatcher misses modifications made after watcher.ready fires

[DanTup]

On Windows I see missed events if we wait for watcher.ready and then modify a file that was very recently created. This code watches for ready then modifies the file, but the watch event is never printed. Adding a fake delay before modifying the file "fixes" the issue.

import 'dart:io';

import 'package:watcher/watcher.dart';

Future<void> main(List<String> arguments) async {
  Directory('tmp').createSync(recursive: true);
  final file = File('tmp/file1')
    ..createSync()
    ..writeAsString('one');
  final watcher = FileWatcher(file.path);
  final sub = watcher.events.listen((event) {
    print(event.type);
  });

  // Wait for watcher to be ready so we do not miss events.
  await watcher.ready;

  // Uncommenting this fixes the issue.
  // await Future.delayed(const Duration(seconds: 5));

  // Write to the file - this should be detected.
  file.writeAsString('two');

  await Future.delayed(const Duration(seconds: 5));

  await sub.cancel();
}