LanguageFeatures/Set-literals/disambiguating_A07_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 Let e be a setOrMapLiteral.
/// If e has a context C, and the base type of C is Cbase (that is, Cbase is C
/// with all wrapping FutureOrs removed), and Cbase is not ?, then let S be the
/// greatest closure.
/// ...
/// if e has no typeArguments, no useful context type, and no elements, then e is
/// treated as a map literal with unknown static type. In other words, an
/// empty {} is a map unless we have a context that indicates otherwise
///
/// @description Checks that an empty {} is a map unless we have a context that
/// indicates otherwise
/// @author sgrekhov@unipro.ru

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

main() {
  var x = {};
  Expect.isTrue(x is Map);
  Expect.isTrue({} is Map<dynamic, dynamic>);
  Expect.runtimeIsType<Map>(x);
  Expect.runtimeIsType<Map<dynamic, dynamic>>({});
}