LanguageFeatures/Spread-collections/StaticSemantic_A02_t01.dart

// Copyright (c) 2019, 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 This is true even if the object being spread is a user-defined
/// class that implements [Iterable] but isn't even a subtype of List.
///
/// @description Checks that [Iterable] object can be spread into the spreadable
/// list.
/// @author iarkh@unipro.ru

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

class MyIterable extends IterableBase {

  MyIterable();

  Iterator get iterator => MyIterator();
}

class MyIterator implements Iterator {
  int i = -1;

  MyIterator() {}

  @override
  bool moveNext() { return ++i < 10; }

  @override
  dynamic get current { return i; }
}

main() {
  Iterable iterable = new MyIterable();
  Expect.listEquals(iterable?.toList(), [...iterable]);
//                          ^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
  Expect.listEquals(iterable?.toList(), [...?iterable]);
//                          ^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
//                                       ^^^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
}