dart-sdk/tests/language/extension_type/field_promotion_representation_conflicts_test.dart

// Copyright (c) 2023, 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.

// Tests that if the representation variable has the same name as other
// non-promotable things in the file, it may nonetheless undergo field promotion
// (this is sound because extension types are resolved statically, so there is
// no danger of the representation variable aliasing to some other declaration,
// as there is for ordinary fields).

import '../static_type_helper.dart';

class C1 {
  int? _f = 0;
}

class C2 {
  int? get _f => 0;
}

class C3 implements C2 {
  noSuchMethod(invocation) => 0;
}

extension type E(Object Function() _f) {
  testImplicitThisAccess() {
    if (_f is int Function()) {
      _f.expectStaticType<Exactly<int Function()>>();
      _f().expectStaticType<Exactly<int>>();
    }
  }

  testExplicitThisAccess() {
    if (this._f is int Function()) {
      this._f.expectStaticType<Exactly<int Function()>>();
      this._f().expectStaticType<Exactly<int>>();
    }
  }
}

testGeneralPropertyAccess(E e) {
  if ((e)._f is int Function()) {
    (e)._f.expectStaticType<Exactly<int Function()>>();
    (e)._f().expectStaticType<Exactly<int>>();
  }
}

testPrefixedIdentifierAccess(E e) {
  // Note: the analyzer has a special representation for property accesses of
  // the form `IDENTIFIER.IDENTIFIER`, so we test this form separately.
  if (e._f is int Function()) {
    e._f.expectStaticType<Exactly<int Function()>>();
    e._f().expectStaticType<Exactly<int>>();
  }
}

main() {
  int Function() f = () => 0;
  E(f).testImplicitThisAccess();
  E(f).testExplicitThisAccess();
  testGeneralPropertyAccess(E(f));
  testPrefixedIdentifierAccess(E(f));
}