dart-sdk/tests/language/async/covariant_type_test.dart
Robert Nystrom 16f072c783 Migrate language_2/async to NNBD.
Change-Id: Id66e712eaf52fda2069ce5177aa091e373ad52c1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134244
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>
2020-02-27 23:04:03 +00:00

21 lines
574 B
Dart

// Copyright (c) 2018, 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.
// Test that TypeErrors happen for async methods without using returned Future.
import 'dart:async';
import 'package:expect/expect.dart';
class D<T> {
// Parametric covariance check is usually compiled into method.
Future<T> add(T n) async {
return n;
}
}
main() async {
D<num> d = new D<int>();
Expect.throwsTypeError(() => d.add(4.6));
}