blob: a198af44489dc1aa9436c082e02e65de2bda61a2 [file] [log] [blame]
// 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 From the Unified collections Spec:
/// We require that at least one component unambiguously determine the literal
/// form, otherwise it is a compile-time error. So, given:
/// dynamic x = <int, int>{};
/// Iterable l = [];
/// Map m = {};
/// Then:
/// {...x} // Static error, because it is ambiguous.
/// {...x, ...l} // Statically a set, runtime error when spreading x.
/// {...x, ...m} // Statically a map, no runtime error.
/// {...l, ...m} // Static error, because it must be both a set and a map.
/// @description Checks that if one of the spreadable element is [Map], result
/// is statically [Map]
/// @author
import "../../Utils/expect.dart";
main() {
dynamic map = <int, int>{};
dynamic set = <int>{};
Map m = {};
Map res;
Expect.throws(() => res = {...m, ...set});
Expect.throws(() => res = {...set, ...m});
Expect.isTrue({, ...m} is Map);
Expect.runtimeIsType<Map>({, ...m});
Expect.isTrue({...m,} is Map);