Shelf hot reload

hot_reload.dart

import 'dart:io';
import 'dart:developer' as dev;
import 'package:shelf/shelf_io.dart' as io;
import 'package:shelf/shelf.dart' as shelf;
import 'package:vm_service/utils.dart';
import 'package:vm_service/vm_service.dart';
import 'package:vm_service/vm_service_io.dart';
import 'package:watcher/watcher.dart';
import 'package:stream_transform/stream_transform.dart';

main() async {
  var httpServer = await io.serve(
      (request) async => shelf.Response.ok('My shelf handler'),
      InternetAddress.anyIPv4,
      0);

  var observatoryUri = (await dev.Service.getInfo()).serverUri;
  if (observatoryUri != null) {
    var serviceClient = await vmServiceConnectUri(
        convertToWebSocketUrl(serviceProtocolUrl: observatoryUri).toString(),
        log: StdoutLog());
    var vm = await serviceClient.getVM();
    var mainIsolate = vm.isolates.first;

    Watcher(Directory.current.path)
        .events
        .throttle(const Duration(milliseconds: 1000))
        .listen((_) async {
      await serviceClient.reloadSources(mainIsolate.id);

      // TODO: invalidate cache etc...
      print('App restarted ${DateTime.now()}');
    });
  } else {
    print(
        'You need to pass `--enable-vm-service --disable-service-auth-codes` to enable hot reload');
  }
}

class StdoutLog extends Log {
  void warning(String message) => print(message);

  void severe(String message) => print(message);
}