tests/corelib/iterable_skip_test.dart

// Copyright (c) 2012, 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.

main() {
  List<int> list1 = <int>[1, 2, 3];
  List<int> list2 = const <int>[4, 5];
  List<String> list3 = <String>[];
  Set<int> set1 = new Set<int>();
  set1..add(11)
      ..add(12)
      ..add(13);
  Set set2 = new Set();

  Iterable<int> skip0 = list1.skip(0);
  Expect.isTrue(skip0 is List);
  Iterator<int> it = skip0.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(1, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(2, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  Iterable<int> skip1 = list1.skip(1);
  Expect.isTrue(skip1 is List);
  Expect.isTrue(skip1.skip(2).skip(1) is List);
  it = skip1.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(2, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  Iterable<int> skip2 = list1.skip(2);
  Expect.isTrue(skip2 is List);
  Expect.isTrue(skip2.skip(2).skip(1) is List);
  it = skip2.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  Iterable<int> skip3 = list1.skip(3);
  Expect.isTrue(skip3 is List);
  Expect.isTrue(skip3.skip(2).skip(1) is List);
  it = skip3.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  Iterable<int> skip4 = list1.skip(4);
  Expect.isTrue(skip4 is List);
  Expect.isTrue(skip4.skip(2).skip(1) is List);
  it = skip4.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip0 = list1.skip(0);
  skip1 = skip0.skip(1);
  skip2 = skip1.skip(1);
  skip3 = skip2.skip(1);
  skip4 = skip3.skip(1);
  it = skip0.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(1, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(2, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);
  it = skip1.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(2, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);
  it = skip2.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(3, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);
  it = skip3.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);
  it = skip4.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip0 = list2.skip(0);
  Expect.isTrue(skip0 is List);
  Expect.isTrue(skip0.skip(2).skip(1) is List);
  it = skip0.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(4, it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(5, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip1 = list2.skip(1);
  Expect.isTrue(skip1 is List);
  Expect.isTrue(skip1.skip(2).skip(1) is List);
  it = skip1.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.equals(5, it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip2 = list2.skip(2);
  Expect.isTrue(skip2 is List);
  Expect.isTrue(skip2.skip(2).skip(1) is List);
  it = skip2.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip3 = list2.skip(3);
  Expect.isTrue(skip3 is List);
  Expect.isTrue(skip3.skip(2).skip(1) is List);
  it = skip3.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  Iterable<String> skip02 = list3.skip(0);
  Expect.isTrue(skip02 is List);
  Expect.isTrue(skip02.skip(2).skip(1) is List);
  Iterator<String> it2 = skip02.iterator;
  Expect.isNull(it2.current);
  Expect.isFalse(it2.moveNext());
  Expect.isNull(it2.current);

  Iterable<String> skip12 = list3.skip(1);
  Expect.isTrue(skip12 is List);
  Expect.isTrue(skip12.skip(2).skip(1) is List);
  it2 = skip12.iterator;
  Expect.isNull(it2.current);
  Expect.isFalse(it2.moveNext());
  Expect.isNull(it2.current);

  skip0 = set1.skip(0);
  List<int> copied = skip0.toList();
  Expect.equals(3, copied.length);
  Expect.isTrue(set1.contains(copied[0]));
  Expect.isTrue(set1.contains(copied[1]));
  Expect.isTrue(set1.contains(copied[2]));
  Expect.isTrue(copied[0] != copied[1]);
  Expect.isTrue(copied[0] != copied[2]);
  Expect.isTrue(copied[1] != copied[2]);
  it = skip0.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip1 = set1.skip(1);
  copied = skip1.toList();
  Expect.equals(2, copied.length);
  Expect.isTrue(set1.contains(copied[0]));
  Expect.isTrue(set1.contains(copied[1]));
  Expect.isTrue(copied[0] != copied[1]);
  it = skip1.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip2 = set1.skip(2);
  copied = skip2.toList();
  Expect.equals(1, copied.length);
  Expect.isTrue(set1.contains(copied[0]));
  it = skip2.iterator;
  Expect.isNull(it.current);
  Expect.isTrue(it.moveNext());
  Expect.isNotNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip3 = set1.skip(3);
  it = skip3.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip4 = set1.skip(4);
  it = skip4.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip0 = set2.skip(0);
  it = skip0.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);

  skip1 = set2.skip(1);
  it = skip1.iterator;
  Expect.isNull(it.current);
  Expect.isFalse(it.moveNext());
  Expect.isNull(it.current);
}