LibTest/async/Stream/where_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> where(bool test(T event))
 * Creates a new stream from this stream that discards some data events.
 * The new stream sends the same error and done events as this stream, but it
 * only sends the data events that satisfy the test.
 * @description Checks that the new stream sends the same error and done events
 * as this stream.
 * @author kaigorodov
 */
library where_A01_t02;

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

void check<T>(Stream<T> s, bool test(T event), List<T> expectedData,
    List expectedErrors) {
  AsyncExpect.events(expectedData, expectedErrors, s.where(test));
}

void test(CreateStreamWithErrorsFunction create) {
  check(create([1, 2, 3, 4, 5], isError: (x) => true, defVal: 42), (e) => true,
      [], [1, 2, 3, 4, 5]);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defVal: 42),
      (e) => true, [1, 3, 5], [2, 4]);
  check<int>(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defVal: 42),
      (e) => e > 1, [3, 5], [2, 4]);
  check(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defVal: 42),
      (e) => false, [], [2, 4]);
  check<int>(create<int>([1, 2, 3, 4, 5], isError: (x) => x.isEven, defVal: 42),
      (e) => throw e, [], [1, 2, 3, 4, 5]);
}