LanguageFeatures/Extension-methods/extension_member_resolution_t02.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.

// @dart = 2.9

/// @assertion For any member access, x.foo, x.bar(), x.baz = 42, x(42), x[0] = 1
/// or x + y, including null-aware and cascade accesses which effectively desugar
/// to one of those direct accesses, and including implicit member accesses on
/// this, the language first checks whether the static type of x has a member
/// with the same base name as the operation. That is, if it has a corresponding
/// instance member, respectively, a foo method or getter or a foo= setter, a bar
/// member or bar= setter, a baz member or baz= setter, a call method, a
/// []= operator or a + operator. If so, then the operation is unaffected by
/// extensions. This check does not care whether the invocation is otherwise
/// correct, based on number or type of the arguments, it only checks whether
/// there is a member at all.
///
/// @description Check that dynamic invocation doesn't invoke any extension
/// method
/// @author sgrekhov@unipro.ru

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

class C {
  String log;
  String method(int i) => "$i";
  noSuchMethod(Invocation i) {
    log = "C NSM invoked. Number of arguments ${i.positionalArguments.length}";
  }
}

extension on C {
  String method(int i, String s) {
    this.log = "Extension on C: $i $s";
  }
}

extension on dynamic {
  String method(int i, String s) {
    this.log = "Extension on dynamic: $i $s";
  }
}

main() {
  dynamic c = new C();
  c.method(42, "-42");
  Expect.equals("C NSM invoked. Number of arguments 2", c.log);
}