js_interop/test/pair_test.dart

// Copyright (c) 2026, 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.

import 'dart:js_interop';

import 'package:js_interop/js_interop.dart';
import 'package:test/test.dart';

void main() {
  late JSPair<JSNumber, JSString> pair;
  setUp(() {
    pair = JSPair(1.toJS, 'foo'.toJS);
  });

  test('\$1 returns the first element', () => expect(pair.$1, equals(1.toJS)));

  test('\$1= sets the first element', () {
    pair.$1 = 2.toJS;
    expect(pair.$1, equals(2.toJS));
  });

  test(
    '\$2 returns the second element',
    () => expect(pair.$2, equals('foo'.toJS)),
  );

  test('\$2= sets the second element', () {
    pair.$2 = 'bar'.toJS;
    expect(pair.$2, equals('bar'.toJS));
  });

  test(
    'toDart returns a Dart record',
    () => expect(pair.toDart, equals((1.toJS, 'foo'.toJS))),
  );

  test('toArray returns a JS array', () {
    final array = pair.toArray;
    expect(array[0], equals(1.toJS));
    expect(array[1], equals('foo'.toJS));
    expect(array.length, equals(2));

    // Array should be a copy
    array[0] = 2.toJS;
    expect(pair.$1, equals(1.toJS));
  });

  test('Record.toJS returns a JSPair', () {
    final pair = (2.toJS, 'bar'.toJS).toJS;
    expect(pair.$1, equals(2.toJS));
    expect(pair.$2, equals('bar'.toJS));
  });
}