JSTests/test262/test/built-ins/Temporal/PlainYearMonth/prototype/toString/options-undefined.js

// Copyright (C) 2021 Igalia, S.L. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
esid: sec-temporal.plainyearmonth.prototype.tostring
description: Verify that undefined options are handled correctly.
features: [Temporal]
---*/

const calendar = {
  toString() { return "custom"; }
};
const yearmonth1 = new Temporal.PlainYearMonth(2000, 5);
const yearmonth2 = new Temporal.PlainYearMonth(2000, 5, calendar);

[
  [yearmonth1, "2000-05"],
  [yearmonth2, "2000-05-01[u-ca=custom]"],
].forEach(([yearmonth, expected]) => {
  const explicit = yearmonth.toString(undefined);
  assert.sameValue(explicit, expected, "default calendarName option is auto");

  const implicit = yearmonth.toString();
  assert.sameValue(implicit, expected, "default calendarName option is auto");
});