LanguageFeatures/nnbd/extension_method_resolution_A03_t02.dart

/*
 * Copyright (c) 2020, 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 For the purposes of extension method resolution, there is no
 * special treatment of nullable types with respect to what members are
 * considered accessible. That is, the only members of a nullable type that are
 * considered accessible (and hence which take precedence over extensions) are
 * the members on Object.
 *
 * @description Check that extension members are called for null value
 * @author sgrekhov@unipro.ru
 * @issue 41349
 */
// Requirements=nnbd-strong

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

class C {
  String m = "";
  String get getter => "C getter";
  void set setter(String v) {
    m = v;
  }

  String method(int i) => "$i";
  void operator []=(int index, String value) {
    m = "[$index]=$value";
  }
}

extension on C? {
  String get getter => "Extension getter";
  String get m => "m getter";
  void set setter(String v) {}
  void set m(String v) {}
  String method(int i) => "Extension: $i";
  void operator []=(int index, String value) {}
}

main() {
  C? c = null;
  Expect.equals("Extension getter", c.getter);
  c.m = "Lily was here";
  Expect.equals("m getter", c.m);
  c.setter = "Run, Forrest, run";
  Expect.equals("m getter", c.m);
  Expect.equals("Extension: 42", c.method(42));
  c[42] = "xxx";
  Expect.equals("m getter", c.m);
}