LibTest/async/Stream/take_A01_t02.test.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 Stream<T> take(int count)
/// Provides at most the first n values of this stream.
/// Forwards the first n data events of this stream, and all error events, to
/// the returned stream, and ends with a done event.
/// If this stream produces fewer than count values before it's done, so will
/// the returned stream.
/// @description Checks that all error events (which are before first n data
/// events) are submitted to the returned stream. Checks that the resulting
/// stream ends with a done event.
/// @author a.semenov@unipro.ru

library take_A01_t02;

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

void  check<T>(
    Stream<T> s, int count, List<T> expectedData, List expectedErrors) {
  AsyncExpect.events(expectedData, expectedErrors, s.take(count));
}

void test(CreateStreamWithErrorsFunction create) {
  check(create([1, 2, 3], isError: (_) => true, defaultValue: 42), 0, [], []);
  check(create([1, 2, 3], isError: (_) => true, defaultValue: 42),
      1, [], [1, 2, 3]);
  check(create([1, 2, 3], isError: (_) => true, defaultValue: 42),
      10, [], [1, 2, 3]);

  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isOdd, defaultValue: 42),
      10, [2, 4], [1, 3, 5]);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isOdd, defaultValue: 42),
      2, [2, 4], [1, 3]);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defaultValue: 42),
      1, [1], []);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defaultValue: 42),
      2, [1, 3], [2]);

  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x < 4, defaultValue: 42),
      1, [4], [1, 2, 3]);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x > 2, defaultValue: 42),
      2, [1, 2], []);
}