LibTest/isolate/ReceivePort/fold_A01_t01.dart

// Copyright (c) 2011, 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.

/**
 * @assertion Future fold(initialValue, combine(previous, T element))
 * Reduces a sequence of values by repeatedly applying combine.
 * @description Checks that the result is correct.
 * @author kaigorodov
 */
import "dart:async";
import "../../../Utils/expect.dart";
import "IsolateStream.dart" as IsolateStream;

void check(Iterable data, initialValue, combine(var previous, var element),
    var expected) {
  Stream s = IsolateStream.fromIterable(data);
  asyncStart();
  Future f = s.fold(initialValue, combine);
  f.then((var actual) {
    Expect.equals(expected, actual);
    asyncEnd();
  });
}

main() {
  check([1, 2, 3, 4], 0, (var previous, var element) => previous + element, 10);
  check([1, 2, 3, 4], 1, (var previous, var element) => previous * element, 24);
}