Language/Types/Function_Types/subtype_named_args_t12.dart

// Copyright (c) 2011, 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 The function type (T1, ... Tn, {Tx1 x1, ..., Txk xk}) -> T is a
/// subtype of the function type (S1, ..., Sn, {Sy1 y1, ..., Sym ym }) -> S, if
/// all of the following conditions are met:
/// 1. Either
///    • S is void, Or
///    • T ⇐⇒ S.
/// 2. ∀i ∈ 1..n, Ti ⇐⇒ Si .
/// 3. k ≥ m and yi ∈ {x1 , ..., xk }, i ∈ 1..m.
/// 4. For all yi ∈ {y1 , ..., ym }, yi = xj ⇒ Tj ⇐⇒ Si.
/// @description Checks that this statement is true for quite complex function
/// types: non-dynamic return type and a bunch of required and named optional
/// parameters.
/// This test is like A03/t04, but the order of named parameters is not altered.
/// @author kaigorodov

import "../../../Utils/expect.dart";

class A {}
class A1 {}
class A2 {}
class B implements A, A1, A2 {}
class C implements B {}
class D implements C {}

typedef B func(Object o);
typedef B t1(int i, B b, Map<int, num> m, var x,
             {var ox, B? ob, List<num>? ol, bool? obool});

B f1(int i, B b, Map<int, num> m, var x,
     {var ox, A? ob, List<num>? ol, bool? obool, extraParam}) => new B();
D f2(int i, D b, Map<int, int> m, func x,
     {func? ox, D? ob, List<int>? ol, bool? obool}) => new D();
C f4(num i, A b, Map<Object, Object> m, var x,
     {var ox, A2? ob, List? ol, bool? obool, A? xx, B? yy}) => new C();

main() {
  Expect.isTrue(f1 is t1);
  Expect.isFalse(f2 is t1);
  Expect.isTrue(f4 is t1);
  Expect.runtimeIsType<t1>(f1);
  Expect.runtimeIsNotType<t1>(f2);
  Expect.runtimeIsType<t1>(f4);
}