text: // Copyright (C) 2021 the V8 project authors. All rights reserved.
  // This code is governed by the BSD license found in the LICENSE file.
  
  /*---
  esid: sec-temporal.calendar.prototype.mergefields
  description: >
    The default mergeFields algorithm from the ISO 8601 calendar should correctly
    merge the month and monthCode properties
  info: |
    1. Let calendar be the this value.
    2. Perform ? RequireInternalSlot(calendar, [[InitializedTemporalCalendar]]).
    3. Assert: calendar.[[Identifier]] is "iso8601".
    4. Set fields to ? ToObject(fields).
    5. Set additionalFields to ? ToObject(additionalFields).
    6. Return ? DefaultMergeFields(fields, additionalFields).
  features: [Temporal]
  includes: [deepEqual.js]
  ---*/
  
  const cal = new Temporal.Calendar("iso8601");
  
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7 }, { b: 3, c: 4 }),
    { a: 1, b: 3, c: 4, month: 7 },
    "month is copied from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, monthCode: "M08" }, { b: 3, c: 4 }),
    { a: 1, b: 3, c: 4, monthCode: "M08" },
    "monthCode is copied from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7, monthCode: "M08" }, { b: 3, c: 4 }),
    { a: 1, b: 3, c: 4, month: 7, monthCode: "M08" },
    "both month and monthCode are copied from fields, no validation is performed"
  );
  
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2 }, { b: 3, c: 4, month: 5 }),
    { a: 1, b: 3, c: 4, month: 5 },
    "month is copied from additionalFields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2 }, { b: 3, c: 4, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, monthCode: "M06" },
    "monthCode is copied from additionalFields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2 }, { b: 3, c: 4, month: 5, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, month: 5, monthCode: "M06" },
    "both month and monthCode are copied from additionalFields, no validation is performed"
  );
  
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7 }, { b: 3, c: 4, month: 5 }),
    { a: 1, b: 3, c: 4, month: 5 },
    "month from additionalFields overrides month from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, monthCode: "M07" }, { b: 3, c: 4, monthCode: "M05" }),
    { a: 1, b: 3, c: 4, monthCode: "M05" },
    "monthCode from additionalFields overrides monthCode from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, monthCode: "M07" }, { b: 3, c: 4, month: 6 }),
    { a: 1, b: 3, c: 4, month: 6 },
    "month's presence on additionalFields blocks monthCode from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7 }, { b: 3, c: 4, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, monthCode: "M06"},
    "monthCode's presence on additionalFields blocks month from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7, monthCode: "M08" },{ b: 3, c: 4, month: 5 }),
    { a: 1, b: 3, c: 4, month: 5 },
    "month's presence on additionalFields blocks both month and monthCode from fields"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7, monthCode: "M08" }, { b: 3, c: 4, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, monthCode: "M06" },
    "monthCode's presence on additionalFields blocks both month and monthCode from fields"
  );
  
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7 }, { b: 3, c: 4, month: 5, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, month: 5, monthCode: "M06" },
    "both month and monthCode are copied from additionalFields even when fields has month"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, monthCode: "M07" }, { b: 3, c: 4, month: 5, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, month: 5, monthCode: "M06" },
    "both month and monthCode are copied from additionalFields even when fields has monthCode"
  );
  assert.deepEqual(
    cal.mergeFields({ a: 1, b: 2, month: 7, monthCode: "M08" }, { b: 3, c: 4, month: 5, monthCode: "M06" }),
    { a: 1, b: 3, c: 4, month: 5, monthCode: "M06" },
    "both month and monthCode are copied from additionalFields even when fields has both month and monthCode"
  );
  