// 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.

int? lateTopLevelField1Init() => 123;
late int? lateTopLevelField1 = lateTopLevelField1Init();

class Class<T> {
  static int? lateStaticField1Init() => 87;
  static late int? lateStaticField1 = lateStaticField1Init();
  static int? lateStaticField2Init() => 42;
  static late int? lateStaticField2 = lateStaticField2Init();

  static staticMethod() {
    expect(42, lateStaticField2);
    lateStaticField2 = 43;
    expect(43, lateStaticField2);
  }

  int? lateInstanceFieldInit() => 16;
  late int? lateInstanceField = lateInstanceFieldInit();

  final T? field;
  T? lateGenericInstanceFieldInit() => field;
  late T? lateGenericInstanceField = lateGenericInstanceFieldInit();

  Class(this.field);

  instanceMethod(T? value) {
    expect(16, lateInstanceField);
    lateInstanceField = 17;
    expect(17, lateInstanceField);

    expect(field, lateGenericInstanceField);
    lateGenericInstanceField = value;
    expect(value, lateGenericInstanceField);
  }
}

extension Extension<T> on Class<T> {
  static int? lateExtensionField1Init() => 87;
  static late int? lateExtensionField1 = lateExtensionField1Init();
  static int? lateExtensionField2Init() => 42;
  static late int? lateExtensionField2 = lateExtensionField2Init();

  static staticMethod() {
    expect(42, lateExtensionField2);
    lateExtensionField2 = 43;
    expect(43, lateExtensionField2);
  }
}

main() {
  expect(123, lateTopLevelField1);
  lateTopLevelField1 = 124;
  expect(124, lateTopLevelField1);

  expect(87, Class.lateStaticField1);
  Class.lateStaticField1 = 88;
  expect(88, Class.lateStaticField1);

  Class.staticMethod();
  new Class<int?>(null).instanceMethod(0);
  new Class<int?>(0).instanceMethod(null);
  new Class<int>(null).instanceMethod(0);
  new Class<int>(0).instanceMethod(null);

  expect(87, Extension.lateExtensionField1);
  Extension.lateExtensionField1 = 88;
  expect(88, Extension.lateExtensionField1);

  Extension.staticMethod();
}

expect(expected, actual) {
  if (expected != actual) throw 'Expected $expected, actual $actual';
}