dnys1

class ServiceManager {
  final _instances = <Type, Object>{};
  
  void register<T extends Object>(T instance) {
    _instances[T] = instance;
  }
  
  bool isRegistered<T extends Object>() {
    return isRegisteredByType(T);
  }

dnys1

enum ABC { a, b, c }

void main() {
  switch (ABC.a) {
    case ABC.a:
      print('a');
    case != ABC.a:
      print('b or c');
  }
}

dnys1

import 'dart:async';

void main() async {
  // A function marked async will implicitly return a Future.
  future(sync: true).then(print);
  future(sync: false).then(print);
  print('main (sync)');
  
  // clear pending futures
  await Future<void>.delayed(Duration.zero);

dnys1

sealed class AuthState {}

abstract class AuthUserSignedIn extends AuthState {
  AuthUser get user;
}

abstract class AuthUserSignedOut extends AuthState {
  AuthUser get user;
}

dnys1

enum MfaType { sms, totp }

T _useCurrent<T>(T value) => value;

Future<void> setMfaPreferences({
  Set<MfaType> Function(Set<MfaType>) enabled = _useCurrent,
  MfaType? Function(MfaType?) preferred = _useCurrent,
}) async {
  // TODO
}

dnys1

void main() {
  switch ('hello') {
    case 'hello':
      print("Hello!");
      continue s;
    s: case String _:
      print("It's a string!");
  }
}

dnys1

class Serializable {
  String toJson() => 'json';
}

void main() {
  switch (Serializable() as dynamic) {
    case dynamic(:final Object? Function() toJson):
      print(toJson());
    case _:
     throw ArgumentError('Not serializable');

dnys1

class Serializable {
  String toJson() => 'json';
}

void main() {
  switch (Serializable() as dynamic) {
    case dynamic(:final Object? Function() toJson):
      print(toJson());
    case _:
     throw ArgumentError('Not serializable');

dnys1

abstract class PluginOptions {}

abstract class Plugin<Options extends PluginOptions> {
  Options get options;
}

class MyPluginOptions extends PluginOptions {}

class MyPlugin extends Plugin<MyPluginOptions> {
  static const pluginKey = PluginKey<MyPluginOptions, MyPlugin>();

dnys1

import { PreSignUpTriggerHandler } from "aws-lambda";
import { CognitoIdentityProvider } from "@aws-sdk/client-cognito-identity-provider";

const CLIENT = new CognitoIdentityProvider({});

export const handler: PreSignUpTriggerHandler = async (event) => {
    console.log(`Got event: ${JSON.stringify(event, null, 2)}`);

    const {
        triggerSource,