LanguageFeatures/Subtyping/dynamic/generated/left_null_return_value_A06_t01.dart

// 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 If T1 is 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 be used as a return value of type T1
 * @author sgrekhov@unipro.ru
 */
/*
 * This test is generated from left_null_A06.dart and 
 * return_value_x01.dart.
 * Don't modify it. If you want to change this file, change one of the files 
 * above and then run generator.dart to regenerate the tests.
 */


import '../../utils/common.dart';
// Requirements=nnbd-weak
import "../../utils/legacy_lib.dart";

Null t0Instance = null;
X? t1Instance = new X();

const t1Default = const X();




X? returnValueFunc() => forgetType(t0Instance);

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

  X? testMethod() => forgetType(t0Instance);

  X? get testGetter => forgetType(t0Instance);
}

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


main() {
  X? returnValueLocalFunc() => forgetType(t0Instance);

  returnValueFunc();
  returnValueLocalFunc();

  ReturnValueTest.staticTestMethod();

  new ReturnValueTest().testMethod();
  new ReturnValueTest().testGetter;

  // Test type parameters

  //# <-- NotGenericFunctionType
  new ReturnValueGen<X?>().testMethod();
  new ReturnValueGen<X?>().testGetter;
  //# -->
}