LanguageFeatures/nnbd/local_variable_inference_A01_t01.dart

/*
 * Copyright (c) 2021, 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 Local variables with explicitly written types are given the
 * declared types as written. The declared type of the variable is considered a
 * "type of interest" in the sense defined in the flow analysis specification.
 * If the variable has an initializer (explicit or implicit) and is not final,
 * then the declaration is treated as an assignment for the purposes of
 * promotion.
 *
 * @description Checks that if the local variable has an initializer (explicit
 * or implicit) and is not final, then the declaration is treated as an
 * assignment for the purposes of promotion.
 *
 * @author sgrekhov@unipro.ru
 */
// Requirements=nnbd-strong
import "../../Utils/expect.dart";

class C {
  static void testStatic() {
    int? x = 42;
    x.isEven;
    x = null;
    Expect.isNull(x?.isEven);

    int? y;
    Expect.isNull(y?.isEven);
    x = 42;
    x.isEven;

    late int? z = 42;
    z.isEven;
    z = null;
    Expect.isNull(z?.isEven);
  }

  test() {
    int? x = 42;
    x.isEven;
    x = null;
    Expect.isNull(x?.isEven);

    int? y;
    Expect.isNull(y?.isEven);
    x = 42;
    x.isEven;

    late int? z = 42;
    z.isEven;
    z = null;
    Expect.isNull(z?.isEven);
  }
}

main() {
  int? x = 42;
  x.isEven;
  x = null;
  Expect.isNull(x?.isEven);

  int? y;
  Expect.isNull(y?.isEven);
  x = 42;
  x.isEven;

  late int? z = 42;
  z.isEven;
  z = null;
  Expect.isNull(z?.isEven);

  C.testStatic();
  C().test();
}