text: // 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.duration.prototype.add
  description: >
      Conversion of ISO date-time strings as relativeTo option to
      Temporal.ZonedDateTime or Temporal.PlainDateTime instances
  includes: [temporalHelpers.js]
  features: [Temporal]
  ---*/
  
  const instance = new Temporal.Duration(1, 0, 0, 1);
  
  let relativeTo = "2019-11-01T00:00";
  const result1 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "bare date-time string is a plain relativeTo");
  
  relativeTo = "2019-11-01T00:00Z";
  const result2 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "date-time + Z is a plain relativeTo");
  
  relativeTo = "2019-11-01T00:00-07:00";
  const result3 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "date-time + offset is a plain relativeTo");
  
  relativeTo = "2019-11-01T00:00[-07:00]";
  const result4 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result4, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "date-time + IANA annotation is a zoned relativeTo");
  
  relativeTo = "2019-11-01T00:00Z[-07:00]";
  const result5 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result5, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "date-time + Z + IANA annotation is a zoned relativeTo");
  
  relativeTo = "2019-11-01T00:00+00:00[UTC]";
  const result6 = instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo });
  TemporalHelpers.assertDuration(result6, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, "date-time + offset + IANA annotation is a zoned relativeTo");
  
  relativeTo = "2019-11-01T00:00+04:15[UTC]";
  assert.throws(RangeError, () => instance.add(new Temporal.Duration(0, 0, 0, 0, -24), { relativeTo }), "date-time + offset + IANA annotation throws if wall time and exact time mismatch");
  