| // TODO(multitest): This was automatically migrated from a multitest and may |
| // contain strange or dead code. |
| |
| // Copyright (c) 2017, 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. |
| |
| // This test verifies that for an unnamed async closure, the following three |
| // types are all appropriately matched: |
| // - The static return type |
| // - The return type of reified runtime type of a tearoff of the function or |
| // method |
| // - The reified type of the future returned by the function or method |
| // |
| // Specific attention is paid to the following conditions: |
| // - The static return type is determined by type inference |
| // - The static return type is `dynamic` |
| // - The function or method immediately returns a value or future with a |
| // different type (possibly using `=>` syntax) |
| |
| import 'dart:async'; |
| |
| import 'package:expect/expect.dart'; |
| |
| class A {} |
| |
| class B extends A {} |
| |
| class B2 extends A {} |
| |
| Future quick() async {} |
| |
| Future<A> futureA() => new Future<A>.value(new A()); |
| |
| Future<B> futureB() => new Future<B>.value(new B()); |
| |
| void checkFutureObject(dynamic tearoff) { |
| Expect.isTrue(tearoff is Future<Object> Function()); |
| Expect.isFalse(tearoff is Future<A> Function()); |
| dynamic f = tearoff(); |
| Expect.isTrue(f is Future<Object>); |
| Expect.isFalse(f is Future<A>); |
| } |
| |
| void checkFutureDynamic(dynamic tearoff) { |
| Expect.isTrue(tearoff is Future<dynamic> Function()); |
| Expect.isFalse(tearoff is Future<A> Function()); |
| dynamic f = tearoff(); |
| Expect.isTrue(f is Future<dynamic>); |
| Expect.isFalse(f is Future<A>); |
| } |
| |
| void checkFutureA(dynamic tearoff) { |
| Expect.isTrue(tearoff is Future<A> Function()); |
| Expect.isFalse(tearoff is Future<B> Function()); |
| dynamic f = tearoff(); |
| Expect.isTrue(f is Future<A>); |
| Expect.isFalse(f is Future<B>); |
| } |
| |
| main() { |
| var f_inferred_futureObject = () async { |
| await quick(); |
| if (false) { |
| return 0; |
| } else { |
| return new A(); |
| } |
| }; |
| |
| var f_inferred_A = () async { |
| await quick(); |
| if (false) { |
| return new A(); |
| } else { |
| return new B(); |
| } |
| }; |
| |
| Future<dynamic> Function() f_futureDynamic = () async { |
| await quick(); |
| if (false) { |
| return 0; |
| } else { |
| return new B(); |
| } |
| }; |
| |
| Future<A> Function() f_A = () async { |
| await quick(); |
| if (false) { |
| return new A(); |
| } else { |
| return new B(); |
| } |
| }; |
| |
| Future<A> Function() f_immediateReturn_B = () async { |
| if (false) { |
| return new A(); |
| } else { |
| return new B(); |
| } |
| }; |
| |
| Future<A> Function() f_immediateReturn_FutureB = () async { |
| if (false) { |
| return new A(); |
| } else { |
| return futureB(); |
| } |
| }; |
| |
| Future<A> Function() f_expressionSyntax_B = |
| () async => false ? new A() : new B(); |
| |
| Future<A> Function() f_expressionSyntax_FutureB = |
| () async => false ? futureA() : futureB(); |
| |
| // Not executed |
| void checkStaticTypes() { |
| // Check that f_inferred_futureObject's static return type is |
| // `Future<Object>`, by verifying that its return value can be assigned to |
| // `Future<int>` but not `int`. |
| Future<int> v1 = f_inferred_futureObject(); |
| |
| |
| // Check that f_inferred_A's static return type is `Future<A>`, by verifying |
| // that its return value can be assigned to `Future<B2>` but not |
| // `Future<int>`. |
| Future<B2> v3 = f_inferred_A(); |
| |
| } |
| |
| checkFutureObject(f_inferred_futureObject); |
| checkFutureA(f_inferred_A); |
| checkFutureDynamic(f_futureDynamic); |
| checkFutureA(f_A); |
| checkFutureA(f_immediateReturn_B); |
| checkFutureA(f_immediateReturn_FutureB); |
| checkFutureA(f_expressionSyntax_B); |
| checkFutureA(f_expressionSyntax_FutureB); |
| } |