Language/Types/Function_Types/subtype_optional_args_t03.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 A function type (T1,...Tk,[Tk+1,...,Tn+m]) -> T is a subtype of
/// the function type (S1,...,Sk+j,[Sk+j+1,...,Sn]) -> S, if all of the following
/// conditions are met:
/// 1. Either
///    • S is void, or
///    • T <=> S.
/// 2. ∀i ∈ 1..n, Ti ⇐⇒ Si.
/// @description Checks that this statement is true even if the subtype function
/// type has more positional optional parameters than the supertype as long as the
/// supertype's positional optional parameters match the beginning of the list of
/// subtype's positional optional parameters.
/// @author iefremov

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

class A {}

class A1 {}

class A2 {}

class B implements A, A1, A2 {}

class C implements B {}

class D implements C {}

class G<T, S, U, W> {}

typedef classesFunc(A aa, [A? a, B? b, C? c, D? d]);
typedef genericsFunc([Map<num, int>? m, List<List<B>>? l, G<A, B, C, D>? g]);
typedef dynamicFunc([var x, var y, var z, var v]);
typedef funcFunc([classesFunc? f1, genericsFunc? f2, dynamicFunc? f3]);
typedef mixFunc([var x, B? b, G<A, B, C, D>? g, funcFunc? f]);

typedef okWithClassesFunc_1(A aa, [A? a, A1? b, A1? c, A1? d]);
typedef okWithClassesFunc_2(A aa, [D? a, D? b, D? c, D? d]);

typedef okWithGenericsFunc_1(
    [Map<num, num>? m, List<List<A1>>? l, G<A, A1, A1, A1>? g]);
typedef okWithGenericsFunc_2(
    [Map<int, int>? m, List<List<D>>? l, G<D, D, D, D>? g]);

typedef okWithDynamicFunc_1([A? x, G? y, mixFunc z, var v]);
typedef okWithDynamicFunc_2([int? x, bool? y, List<Map>? z, classesFunc? v]);

main() {
  Expect.isFalse((var vv,
      [D? a,
      B? b,
      C? c,
      A? d,
      var xx,
      Map? xxx,
      Object? xxxx]) {} is classesFunc);
  Expect.runtimeIsNotType<classesFunc>(
      (var vv, [A? a, C? c, B? b, D? d, Map? xxx, Object? xxxx]) {});

  Expect.isTrue(
      ([var m, var l, var g, var xx, var xxx, var xxxx]) {} is genericsFunc);
  Expect.runtimeIsType<genericsFunc>(
      ([var m, var l, var g, var xx, var xxx, var xxxx]) {});
  Expect.runtimeIsType<genericsFunc>(
      ([var m, var l, var g, var xx, var xxx, var xxxx]) {});
  Expect.isFalse((
      [A? x,
      G? y,
      mixFunc? z,
      var v,
      Object? xx,
      List<Map<int, mixFunc>>? xxx,
      mixFunc? xxxx]) {} is dynamicFunc);
  Expect.runtimeIsNotType<dynamicFunc>((
      [A? x,
      G? y,
      mixFunc? z,
      var v,
      Object? xx,
      List<Map<int, mixFunc>>? xxx,
      mixFunc? xxxx]) {});
  Expect.isTrue((
      [okWithClassesFunc_2? f1,
      okWithGenericsFunc_2? f2,
      okWithDynamicFunc_2? f3,
      mixFunc? xx,
      funcFunc? xxx]) {} is funcFunc);
  Expect.runtimeIsType<funcFunc>((
      [okWithClassesFunc_2? f1,
      okWithGenericsFunc_2? f2,
      okWithDynamicFunc_2? f3,
      mixFunc? xx,
      funcFunc? xxx]) {});
}