// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion  Stream asyncMap(dynamic convert(T event))
/// Creates a new stream with each data event of this stream asynchronously
/// mapped to a new event.
///
/// This acts like map, except that convert may return a Future, and in that
/// case, the stream waits for that future to complete before continuing with
/// its result.
///
/// @description Checks that if convert return a Future, the stream waits for
/// that future to complete before continuing with its result.
/// @author ngl@unipro.ru

library asyncMap_A01_t03;
import "dart:async";
import "../../../Utils/expect.dart";

void check<T,E>(Stream<T> s1, List<E> expected) {
  int len = expected.length;
  List<Completer<E>> c = new List.generate(len, (_) => new Completer<E>());
  int i = 0;

  AsyncExpect.data(expected, s1.asyncMap((event) => c[i++].future));

  for (int k = 0; k < len; k++) {
    c[k].complete(expected[k]);
  }
}

void test(CreateStreamFunction create) {
  check(create([]), []);
  check(create([1, 2, 3, 4]), [1, 2, 3, 4]);
  check(create([null, "2", -3, 4.0, []]), [null, "2", -3, 4.0, []]);
}