Language/08_Interfaces/5_Superinterfaces/1_Inheritance_and_Overriding_A02_t01.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 If the above rule would cause multiple members m1 , . . . , mk with
 * the same name n to be inherited (because identically named members existed
 * in several superinterfaces) then at most one member is inherited. 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 numberOfPositionals(f) denote the number of positional parameters
 *   of a function f, and let numberOfRequiredParams(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(numberOfPositionals(mi)),
 *   r = min(numberOfRequiredParams(mi)), i ∈ 1..k.
 *   If r <= h then I has a method named n, with r required parameters of type dynamic,
 *   h optional positional parameters of type dynamic, named parameters s
 *   of type dynamic and return type dynamic.
 * - Otherwise none of the members m1 , . . . , mk is inherited.
 * @description Checks that there's a static warning produced when attempting to access
 * an interface member that is not inherited from either of the two superinterfaces
 * that declare a member with the same name because of the conflict described in this
 * assertion. Members in question are variables of incompatible types.
 * @static-warning
 * @author rodionov
 * @reviewer kaigorodov
 */
import "../../../Utils/expect.dart";

abstract class SI1 {
  int foo;
}

abstract class SI2 {
  String foo;
}

abstract class I implements SI2, SI1 {}

main() {
  I i = null;
  
  try {
    String z=i.foo; /// static type warning
    Expect.fail("NoSuchMethodError expected");
  } on NoSuchMethodError catch(npe) {}
}