Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/inheritance_t13.dart

// 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 define inherited(J, K) to be
 * the set of members m such that all of the following hold:
 * • m is accessible to K and
 * • A is a direct superinterface of J and either
 * – A declares a member m or
 * – m is a member of inherited(A, K).
 * • m is not overridden by J.
 * ...
 * Otherwise, if the static types T1,...,Tk of the members m1,...,mk are not
 * identical, then there must be a member mx such that Tx <: Ti, 1 ≤ x ≤ k for
 * all i ∈ 1..k, or a static type warning occurs. The member that is inherited
 * is mx, if it exists; otherwise: let numberOf P ositionals(f) denote the
 * number of positional parameters of a function f, and let numberOf
 * RequiredParams(f) denote the number of required parameters of a function f.
 * Furthermore, let s denote the set of all named parameters of the m1,...,mk.
 * Then let
 * h = max(numberOf Positionals(mi)),
 * r = min(numberOf RequiredParams(mi)), i ∈ 1..k.
 * Then I has a method named n, with r required parameters of type dynamic,
 * h positional parameters of type dynamic, named parameters s of type dynamic
 * and return type dynamic.
 * @description Checks that there's no static warning produced when the
 * subinterface member being accessed is actually inherited. Members tested
 * include variables, methods, getters, setters and operators. There's no way
 * to check whether the resulting inherited method signature is actually as
 * described above, but we can check that it's inherited at all. Test type
 * aliases
 * @static-clean
 * @author sgrekhov@unipro.ru
 */
// SharedOptions=--enable-experiment=nonfunction-type-aliases
import '../../../../Utils/expect.dart';

class C {}
class D extends C {}

abstract class SI1 {
  int method(num? v, String? p, {int? o1, Pattern? o2});
  int method2(C? v, [D? o]);
  int? get gett0r;
  void set sett0r(int? v);
  C operator +(C v);
}

abstract class SI2 {
  void method(num? v, String? p, {int? o1, Pattern? o2});
  num method2(C? v, [D? o]);
  num? get gett0r;
  void set sett0r(num? v);
  C operator +(C v);
}

typedef SIAlias1 = SI1;
typedef SIAlias2 = SI2;

abstract class I implements SIAlias1, SIAlias2, C {}

main() {
  I? i = null;

  i?.method(null, null, o1:null, o2:null);
  var v = i?.method2(null, null);
  num? n = i?.gett0r;
  i?.sett0r = null;
  Expect.throws(() {var v = (i as I) + (i as I);});
}