tests/lib/html/js_typed_interop_default_arg_test.dart

// Copyright (c) 2015, 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.

@JS()
library js_typed_interop_test;

import 'dart:html';

import 'package:js/js.dart';
import 'package:expect/minitest.dart';

_injectJs() {
  document.body!.append(new ScriptElement()
    ..type = 'text/javascript'
    ..innerHtml = r"""
  var Foo = {
    get42: function(b) { return arguments.length >= 1 ? b : 42; }
  };
""");
}

@JS()
class Foo {
  external static num get42([num? b]);
}

main() {
  _injectJs();

  test('call directly from dart', () {
    expect(Foo.get42(2), 2);
    expect(Foo.get42(), 42);
  });

  test('call tearoff from dart with arg', () {
    var f = Foo.get42;
    expect(f(2), 2);
  });

  test('call tearoff from dart with no arg', () {
    var f = Foo.get42;
    expect(f(), 42);
  });
}