Normative: Update calendar data consistency validation

polyfill/lib/calendar.mjs

@@ -41,6 +41,8 @@ const MapPrototypeEntries = Map.prototype.entries;
 const MapPrototypeGet = Map.prototype.get;
 const MapPrototypeSet = Map.prototype.set;
 const SetPrototypeAdd = Set.prototype.add;
+const SetPrototypeDelete = Set.prototype.delete;
+const SetPrototypeHas = Set.prototype.has;
 const SetPrototypeValues = Set.prototype.values;
 const SymbolIterator = Symbol.iterator;
 const WeakMapPrototypeGet = WeakMap.prototype.get;
@@ -109,12 +111,24 @@ export class Calendar {
   fields(fields) {
     if (!ES.IsTemporalCalendar(this)) throw new TypeError('invalid receiver');
     const fieldsArray = [];
-    const allowed = new Set(['year', 'month', 'monthCode', 'day']);
-    for (const name of fields) {
-      if (ES.Type(name) !== 'String') throw new TypeError('invalid fields');
-      if (!allowed.has(name)) throw new RangeError(`invalid field name ${name}`);
-      allowed.delete(name);
-      ES.Call(ArrayPrototypePush, fieldsArray, [name]);
+    const allowed = new OriginalSet(['year', 'month', 'monthCode', 'day']);
+    const iteratorRecord = ES.GetIterator(fields, 'sync');
+    const abort = (err) => {
+      const completion = new ES.CompletionRecord('throw', err);
+      return ES.IteratorClose(iteratorRecord, completion)['?']();
+    };
+    let next = true;
+    while (next !== false) {
+      next = ES.IteratorStep(iteratorRecord);
+      if (next !== false) {
+        let name = ES.IteratorValue(next);
+        if (ES.Type(name) !== 'String') return abort(new TypeError('invalid fields'));
+        if (!ES.Call(SetPrototypeHas, allowed, [name])) {
+          return abort(new RangeError(`invalid or duplicate field name ${name}`));
+        }
+        ES.Call(SetPrototypeDelete, allowed, [name]);
+        ES.Call(ArrayPrototypePush, fieldsArray, [name]);
+      }
     }
     return impl[GetSlot(this, CALENDAR_ID)].fields(fieldsArray);
   }
@@ -311,11 +325,10 @@ impl['iso8601'] = {
     if (fields.month !== undefined && fields.year === undefined && fields.monthCode === undefined) {
       throw new TypeError('either year or monthCode required with month');
     }
-    const useYear = fields.monthCode === undefined;
     const referenceISOYear = 1972;
     fields = resolveNonLunisolarMonth(fields);
     let { month, day, year } = fields;
-    ({ month, day } = ES.RegulateISODate(useYear ? year : referenceISOYear, month, day, overflow));
+    ({ month, day } = ES.RegulateISODate(year !== undefined ? year : referenceISOYear, month, day, overflow));
     return ES.CreateTemporalMonthDay(month, day, calendarSlotValue, referenceISOYear);
   },
   fields(fields) {
@@ -1922,10 +1935,21 @@ const helperDangi = ObjectAssign({}, { ...helperChinese, id: 'dangi' });
  * ISO and non-ISO implementations vs. code that was very different.
  */
 const nonIsoGeneralImpl = {
+  CalendarFieldDescriptors(type) {
+    let fieldDescriptors = [];
+    if (type !== 'month-day') {
+      fieldDescriptors = [
+        { property: 'era', conversion: ES.ToString, required: false },
+        { property: 'eraYear', conversion: ES.ToIntegerOrInfinity, required: false }
+      ];
+    }
+    return fieldDescriptors;
+  },
   dateFromFields(fields, options, calendarSlotValue) {
     const cache = new OneObjectCache();
-    const fieldNames = this.fields(['day', 'month', 'monthCode', 'year']);
-    fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const fieldNames = ['day', 'month', 'monthCode', 'year'];
+    const extraFieldDescriptors = this.CalendarFieldDescriptors('date');
+    fields = ES.PrepareTemporalFields(fields, fieldNames, [], extraFieldDescriptors);
     const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.calendarToIsoDate(fields, overflow, cache);
     const result = ES.CreateTemporalDate(year, month, day, calendarSlotValue);
@@ -1934,8 +1958,9 @@ const nonIsoGeneralImpl = {
   },
   yearMonthFromFields(fields, options, calendarSlotValue) {
     const cache = new OneObjectCache();
-    const fieldNames = this.fields(['month', 'monthCode', 'year']);
-    fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const fieldNames = ['month', 'monthCode', 'year'];
+    const extraFieldDescriptors = this.CalendarFieldDescriptors('year-month');
+    fields = ES.PrepareTemporalFields(fields, fieldNames, [], extraFieldDescriptors);
     const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.calendarToIsoDate({ ...fields, day: 1 }, overflow, cache);
     const result = ES.CreateTemporalYearMonth(year, month, calendarSlotValue, /* referenceISODay = */ day);
@@ -1946,8 +1971,9 @@ const nonIsoGeneralImpl = {
     const cache = new OneObjectCache();
     // For lunisolar calendars, either `monthCode` or `year` must be provided
     // because `month` is ambiguous without a year or a code.
-    const fieldNames = this.fields(['day', 'month', 'monthCode', 'year']);
-    fields = ES.PrepareTemporalFields(fields, fieldNames, []);
+    const fieldNames = ['day', 'month', 'monthCode', 'year'];
+    const extraFieldDescriptors = this.CalendarFieldDescriptors('date');
+    fields = ES.PrepareTemporalFields(fields, fieldNames, [], extraFieldDescriptors);
     const overflow = ES.ToTemporalOverflow(options);
     const { year, month, day } = this.helper.monthDayFromFields(fields, overflow, cache);
     // `year` is a reference year where this month/day exists in this calendar

polyfill/lib/ecmascript.mjs

@@ -3,6 +3,7 @@
 const ArrayIncludes = Array.prototype.includes;
 const ArrayPrototypePush = Array.prototype.push;
 const ArrayPrototypeSort = Array.prototype.sort;
+const ArrayPrototypeFind = Array.prototype.find;
 const IntlDateTimeFormat = globalThis.Intl.DateTimeFormat;
 const IntlSupportedValuesOf = globalThis.Intl.supportedValuesOf;
 const MathAbs = Math.abs;
@@ -28,13 +29,18 @@ const StringPrototypeSlice = String.prototype.slice;
 import bigInt from 'big-integer';
 import callBound from 'call-bind/callBound';
 import Call from 'es-abstract/2022/Call.js';
+import CompletionRecord from 'es-abstract/2022/CompletionRecord.js';
 import CreateDataPropertyOrThrow from 'es-abstract/2022/CreateDataPropertyOrThrow.js';
 import Get from 'es-abstract/2022/Get.js';
+import GetIterator from 'es-abstract/2022/GetIterator.js';
 import GetMethod from 'es-abstract/2022/GetMethod.js';
 import HasOwnProperty from 'es-abstract/2022/HasOwnProperty.js';
 import IsArray from 'es-abstract/2022/IsArray.js';
 import IsIntegralNumber from 'es-abstract/2022/IsIntegralNumber.js';
 import IsPropertyKey from 'es-abstract/2022/IsPropertyKey.js';
+import IteratorClose from 'es-abstract/2022/IteratorClose.js';
+import IteratorStep from 'es-abstract/2022/IteratorStep.js';
+import IteratorValue from 'es-abstract/2022/IteratorValue.js';
 import SameValue from 'es-abstract/2022/SameValue.js';
 import ToIntegerOrInfinity from 'es-abstract/2022/ToIntegerOrInfinity.js';
 import ToNumber from 'es-abstract/2022/ToNumber.js';
@@ -186,8 +192,6 @@ const BUILTIN_CASTS = new Map([
   ['milliseconds', ToIntegerIfIntegral],
   ['microseconds', ToIntegerIfIntegral],
   ['nanoseconds', ToIntegerIfIntegral],
-  ['era', ToPrimitiveAndRequireString],
-  ['eraYear', ToIntegerOrInfinity],
   ['offset', ToPrimitiveAndRequireString]
 ]);
 
@@ -234,9 +238,14 @@ import * as PARSE from './regex.mjs';
 
 export {
   Call,
+  CompletionRecord,
+  GetIterator,
   GetMethod,
   HasOwnProperty,
   IsIntegralNumber,
+  IteratorClose,
+  IteratorStep,
+  IteratorValue,
   ToIntegerOrInfinity,
   ToNumber,
   ToObject,
@@ -1105,11 +1114,21 @@ export function PrepareTemporalFields(
   bag,
   fields,
   requiredFields,
+  extraFieldDescriptors = [],
   duplicateBehaviour = 'throw',
   { emptySourceErrorMessage = 'no supported properties found' } = {}
 ) {
   const result = ObjectCreate(null);
   let any = false;
+  if (extraFieldDescriptors) {
+    for (let index = 0; index < extraFieldDescriptors.length; index++) {
+      let desc = extraFieldDescriptors[index];
+      Call(ArrayPrototypePush, fields, [desc.property]);
+      if (desc.required === true && requiredFields !== 'partial') {
+        Call(ArrayPrototypePush, requiredFields, [desc.property]);
+      }
+    }
+  }
   Call(ArrayPrototypeSort, fields, []);
   let previousProperty = undefined;
   for (let index = 0; index < fields.length; index++) {
@@ -1123,6 +1142,14 @@ export function PrepareTemporalFields(
         any = true;
         if (BUILTIN_CASTS.has(property)) {
           value = BUILTIN_CASTS.get(property)(value);
+        } else if (extraFieldDescriptors) {
+          const matchingDescriptor = Call(ArrayPrototypeFind, extraFieldDescriptors, [
+            (desc) => desc.property === property
+          ]);
+          if (matchingDescriptor) {
+            const convertor = matchingDescriptor.conversion;
+            value = convertor(value);
+          }
         }
         result[property] = value;
       } else if (requiredFields !== 'partial') {
@@ -1145,7 +1172,9 @@ export function PrepareTemporalFields(
 
 export function ToTemporalTimeRecord(bag, completeness = 'complete') {
   const fields = ['hour', 'microsecond', 'millisecond', 'minute', 'nanosecond', 'second'];
-  const partial = PrepareTemporalFields(bag, fields, 'partial', { emptySourceErrorMessage: 'invalid time-like' });
+  const partial = PrepareTemporalFields(bag, fields, 'partial', undefined, undefined, {
+    emptySourceErrorMessage: 'invalid time-like'
+  });
   const result = {};
   for (let index = 0; index < fields.length; index++) {
     const field = fields[index];

polyfill/lib/plainmonthday.mjs

@@ -83,7 +83,7 @@ export class PlainMonthDay {
     const inputFields = ES.PrepareTemporalFields(item, inputFieldNames, []);
     let mergedFields = ES.CalendarMergeFields(calendar, fields, inputFields);
     const concatenatedFieldNames = ES.Call(ArrayPrototypeConcat, receiverFieldNames, inputFieldNames);
-    mergedFields = ES.PrepareTemporalFields(mergedFields, concatenatedFieldNames, [], 'ignore');
+    mergedFields = ES.PrepareTemporalFields(mergedFields, concatenatedFieldNames, [], [], 'ignore');
     const options = ObjectCreate(null);
     options.overflow = 'reject';
     return ES.CalendarDateFromFields(calendar, mergedFields, options);

polyfill/lib/plainyearmonth.mjs

@@ -125,7 +125,7 @@ export class PlainYearMonth {
     const inputFields = ES.PrepareTemporalFields(item, inputFieldNames, []);
     let mergedFields = ES.CalendarMergeFields(calendar, fields, inputFields);
     const concatenatedFieldNames = ES.Call(ArrayPrototypeConcat, receiverFieldNames, inputFieldNames);
-    mergedFields = ES.PrepareTemporalFields(mergedFields, concatenatedFieldNames, [], 'ignore');
+    mergedFields = ES.PrepareTemporalFields(mergedFields, concatenatedFieldNames, [], [], 'ignore');
     const options = ObjectCreate(null);
     options.overflow = 'reject';
     return ES.CalendarDateFromFields(calendar, mergedFields, options);

spec/abstractops.html

@@ -1804,6 +1804,7 @@ <h1>
         _fields_: an Object,
         _fieldNames_: a List of property names,
         _requiredFields_: ~partial~ or a List of property names,
+        optional _extraFieldDescriptors_: a List of Calendar Field Descriptor Records,
         optional _duplicateBehaviour_: ~throw~ or ~ignore~,
       ): either a normal completion containing an Object, or an abrupt completion
     </h1>
@@ -1813,12 +1814,19 @@ <h1>
         The returned Object has a null prototype, and an own data property for each element of _fieldNames_ that corresponds with a non-*undefined* property of the same name on _fields_ used as the input for relevant conversion.
         When _requiredFields_ is ~partial~, this operation throws if none of the properties are present with a non-*undefined* value.
         When _requiredFields_ is a List, this operation throws if any of the properties named by it are absent or undefined, and otherwise substitutes a relevant default for any absent or undefined non-required property (ensuring that the returned object has a property for each element of _fieldNames_).
+        When _extraFieldDescriptors_ is present, its contents are treated as an extension of <emu-xref href="#table-temporal-field-requirements"></emu-xref>.
       </dd>
     </dl>
     <emu-alg>
       1. If _duplicateBehaviour_ is not present, set _duplicateBehaviour_ to ~throw~.
       1. Let _result_ be OrdinaryObjectCreate(*null*).
       1. Let _any_ be *false*.
+      1. If _extraFieldDescriptors_ is present, then
+        1. For each Calendar Field Descriptor Record _desc_ of _extraFieldDescriptors_, do
+          1. Assert: _fieldNames_ does not contain _desc_.[[Property]].
+          1. Append _desc_.[[Property]] to _fieldNames_.
+          1. If _desc_.[[Required]] is *true* and _requiredFields_ is a List, then
+            1. Append _desc_.[[Property]] to _requiredFields_.
       1. Let _sortedFieldNames_ be SortStringListByCodeUnit(_fieldNames_).
       1. Let _previousProperty_ be *undefined*.
       1. For each property name _property_ of _sortedFieldNames_, do
@@ -1841,6 +1849,9 @@ <h1>
                 1. NOTE: Non-primitive values are supported here for consistency with other fields, but such values must coerce to Strings.
                 1. Set _value_ to ? ToPrimitive(_value_, ~string~).
                 1. If _value_ is not a String, throw a *TypeError* exception.
+            1. Else if _extraFieldDescriptors_ is present and _extraFieldDescriptors_ contains a Calendar Field Descriptor Record _desc_ such that _desc_.[[Property]] is _property_, then
+              1. Let _converter_ be _desc_.[[Conversion]].
+              1. Set _value_ to ? _converter_(_value_).
             1. Perform ! CreateDataPropertyOrThrow(_result_, _property_, _value_).
           1. Else if _requiredFields_ is a List, then
             1. If _requiredFields_ contains _property_, then
@@ -1921,16 +1932,6 @@ <h1>
             <td>~ToPrimitiveAndRequireString~</td>
             <td>*undefined*</td>
           </tr>
-          <tr>
-            <td>*"era"*</td>
-            <td>~ToPrimitiveAndRequireString~</td>
-            <td>*undefined*</td>
-          </tr>
-          <tr>
-            <td>*"eraYear"*</td>
-            <td>~ToIntegerWithTruncation~</td>
-            <td>*undefined*</td>
-          </tr>
           <tr>
             <td>*"timeZone"*</td>
             <td></td>
@@ -1939,6 +1940,36 @@ <h1>
         </tbody>
       </table>
     </emu-table>
+
+    <emu-clause id="sec-temporal-calendar-field-descriptor-record">
+      <h1>Calendar Field Descriptor Record</h1>
+      <p>A <dfn variants="Calendar Field Descriptor Records">Calendar Field Descriptor Record</dfn> is a Record value used to describe a calendar-specific field for use in creating and interacting with instances of Temporal types.</p>
+      <p>Calendar Field Descriptor Records have the fields listed in <emu-xref href="#table-temporal-calendar-field-descriptor-record"></emu-xref>.</p>
+      <emu-table id="table-temporal-calendar-field-descriptor-record" caption="Calendar Field Descriptor Record Fields">
+        <table>
+          <tr>
+            <th>Field Name</th>
+            <th>Value</th>
+            <th>Meaning</th>
+          </tr>
+          <tr>
+            <td>[[Property]]</td>
+            <td>a String</td>
+            <td>The property name associated with the field, analogous to the Property column of <emu-xref href="#table-temporal-field-requirements"></emu-xref>.</td>
+          </tr>
+          <tr>
+            <td>[[Conversion]]</td>
+            <td>an Abstract Closure accepting a single ECMAScript language value and returning either a normal completion containing an ECMAScript language value representing purely static data or a throw completion.</td>
+            <td>The means by which purported values are coerced to a static representation of the correct type (or rejected if that fails), analogous to steps indicated by the Conversion column of <emu-xref href="#table-temporal-field-requirements"></emu-xref>.</td>
+          </tr>
+          <tr>
+            <td>[[Required]]</td>
+            <td>a Boolean</td>
+            <td>Whether PrepareTemporalFields should consider the field as required when not accepting partial data.</td>
+          </tr>
+        </table>
+      </emu-table>
+    </emu-clause>
   </emu-clause>
 
   <emu-clause id="sec-temporal-getdifferencesettings" type="abstract operation">