| // Copyright (c) 2020, 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 We say that a type T0 is a subtype of a type T1 (written T0 <: T1) |
| /// when: |
| /// Left Null: if T0 is Null then: |
| /// - if T1 is a type variable (promoted or not) the query is false |
| /// - If T1 is FutureOr<S> for some S, then the query is true iff Null <: S. |
| /// - If T1 is Null, S? or S* for some S, then the query is true. |
| /// - Otherwise, the query is false |
| /// @description Check that if type T0 is Null and T1 is FutureOr<S> for some S, |
| /// and Null is subtype of S then T0 is subtype of T1. |
| /// @author sgrekhov@unipro.ru |
| /// |
| /// @description Check that if type T0 is a subtype of a type T1, then instance |
| /// of T0 can be used as a return value of type T1 |
| /// @author sgrekhov@unipro.ru |
| /// |
| /// This test is generated from test_types/left_null_A02.dart and |
| /// test_cases/return_value_x01.dart. Don't modify it! |
| /// If you need to change this test, then change one of the files above and then |
| /// run generator/generator.dart to regenerate the tests. |
| |
| import '../../utils/common.dart'; |
| |
| import "dart:async"; |
| |
| Null t0Instance = null; |
| FutureOr<Null> t1Instance = null; |
| |
| const t1Default = null; |
| |
| FutureOr<Null> returnValueFunc() => forgetType(t0Instance); |
| |
| class ReturnValueTest { |
| static FutureOr<Null> staticTestMethod() => forgetType(t0Instance); |
| |
| FutureOr<Null> testMethod() => forgetType(t0Instance); |
| |
| FutureOr<Null> get testGetter => forgetType(t0Instance); |
| } |
| |
| class ReturnValueGen<X> { |
| X testMethod() => forgetType(t0Instance); |
| X get testGetter => forgetType(t0Instance); |
| } |
| |
| main() { |
| FutureOr<Null> returnValueLocalFunc() => forgetType(t0Instance); |
| |
| returnValueFunc(); |
| returnValueLocalFunc(); |
| |
| ReturnValueTest.staticTestMethod(); |
| |
| new ReturnValueTest().testMethod(); |
| new ReturnValueTest().testGetter; |
| |
| // Test type parameters |
| |
| new ReturnValueGen<FutureOr<Null>>().testMethod(); |
| new ReturnValueGen<FutureOr<Null>>().testGetter; |
| } |