LibTest/core/Iterable/single_A01_t01.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 E single
/// Returns the single element in this.
/// If this is empty or has more than one element throws a StateError.
/// @description Checks that the single element is returned.
/// Checks that StateError is thrown if this list is empty or has more than one
/// element
/// @author kaigorodov

library single_A01_t01;

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

test(Iterable create([Iterable content])) {
  void check(List content) {
    Iterable a = create(content);
    if (a.length == 1) {
      Expect.equals(a.elementAt(0), a.single);
    } else {
      Expect.throws(() {a.single;}, (e) => e is StateError);
    }
  }
  check([]);
  List a = new List.empty(growable: true);
  check(a);
  a.add(0);
  check(a);
  a.length = 25476;
  check(a);
  a.clear();
  a.length = 1;
  check(a);
  a = const[];
  check(a);
  a = const[1];
  check(a);
}