// 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 We say that a type T0 is a subtype of a type T1 (written T0 <: T1)
/// when:
/// Right Object: if T1 is Object then:
///  - if T0 is an unpromoted type variable with bound B then T0 <: T1 iff
///      B <: Object
///  - if T0 is a promoted type variable X & S then T0 <: T1 iff S <: Object
///  - if T0 is FutureOr<S> for some S, then T0 <: T1 iff S <: Object.
///  - if T0 is S* for any S, then T0 <: T1 iff S <: T1
///  - if T0 is Null, dynamic, void, or S? for any S, then the subtyping does not
///      hold (per above, the result of the subtyping query is false).
///  - Otherwise T0 <: T1 is true.
/// @description Check that if T0 is FutureOr<S> for some S but S is not subtype
/// of Object then T0 is not subtype of T1
/// @author sgrekhov@unipro.ru
///
/// @description Check that if type T0 not a subtype of a type T1, then instance
/// of T0 cannot be used as a return value of type T1
/// @author sgrekhov@unipro.ru
///
/// This test is generated from test_types/right_object_fail_A07.dart and 
/// test_cases/return_value_fail_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 '../../../../Utils/expect.dart';

// Requirements=nnbd-strong

import "dart:async";

class S {}

FutureOr<S?> t0Instance = null;
Object t1Instance = new Object();

const t1Default = const Object();

Object returnValueFunc() => forgetType(t0Instance);

class ReturnValueTest {
  static Object staticTestMethod() => forgetType(t0Instance);

  Object testMethod() => forgetType(t0Instance);

  Object get testGetter => forgetType(t0Instance);
}

class ReturnValueGen<X> {
  X testMethod() => forgetType(t0Instance);
  X get testGetter => forgetType(t0Instance);
}

main() {
  Object returnValueLocalFunc() => forgetType(t0Instance);

  Expect.throws(() {
    returnValueFunc();
  }, (e) => e is TypeError);
  Expect.throws(() {
    returnValueLocalFunc();
  }, (e) => e is TypeError);
  Expect.throws(() {
    ReturnValueTest.staticTestMethod();
  }, (e) => e is TypeError);

  Expect.throws(() {
    new ReturnValueTest().testMethod();
  }, (e) => e is TypeError);
  Expect.throws(() {
    new ReturnValueTest().testGetter;
  }, (e) => e is TypeError);

  // Test type parameters

  Expect.throws(() {
    new ReturnValueGen<Object>().testMethod();
  }, (e) => e is TypeError);
  Expect.throws(() {
    new ReturnValueGen<Object>().testGetter;
  }, (e) => e is TypeError);
}