Throw TypeError if no overlap between options and Temporal object

Somewhere along the line the spec text got out of sync with the consensus, probably in one of the rebases on newer ECMA-402. When attempting to format a Temporal object, if the DateTimeFormat has options that do not overlap with the data model of the Temporal object, toLocaleString() and format() are supposed to throw a TypeError. Previously, this worked correctly with dateStyle and timeStyle, but not with other options. We would treat the options as if the DateTimeFormat had been created with only default options, which was incorrect. Closes: #2795
tc39 · Oct 4, 2024 · b21ed2d · b21ed2d
1 parent 53d2b63
commit b21ed2d
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Showing 3 changed files with 47 additions and 17 deletions.
diff --git a/polyfill/lib/intl.mjs b/polyfill/lib/intl.mjs
@@ -17,7 +17,8 @@ import {
   ObjectAssign,
   ObjectCreate,
   ObjectDefineProperties,
-  ObjectDefineProperty
+  ObjectDefineProperty,
+  ObjectKeys
 } from './primordials.mjs';
 import { assert } from './assert.mjs';
 import * as ES from './ecmascript.mjs';
@@ -319,8 +320,8 @@ function amend(options = {}, amended = {}) {
   return options;
 }
 
-function timeAmend(options) {
-  options = amend(options, {
+function timeAmend(originalOptions) {
+  const options = amend(originalOptions, {
     year: false,
     month: false,
     day: false,
@@ -329,7 +330,10 @@ function timeAmend(options) {
     dateStyle: false
   });
   if (!hasTimeOptions(options)) {
-    options = ObjectAssign({}, options, {
+    if (hasAnyDateTimeOptions(originalOptions)) {
+      throw new TypeError(`cannot format Temporal.PlainTime with options [${ObjectKeys(originalOptions)}]`);
+    }
+    ObjectAssign(options, {
       hour: 'numeric',
       minute: 'numeric',
       second: 'numeric'
@@ -338,7 +342,7 @@ function timeAmend(options) {
   return options;
 }
 
-function yearMonthAmend(options) {
+function yearMonthAmend(originalOptions) {
   // Try to fake what dateStyle should do for dates without a day. This is not
   // accurate for locales that always print the era
   const dateStyleHacks = {
@@ -347,7 +351,7 @@ function yearMonthAmend(options) {
     long: { year: 'numeric', month: 'long' },
     full: { year: 'numeric', month: 'long' }
   };
-  options = amend(options, {
+  const options = amend(originalOptions, {
     day: false,
     hour: false,
     minute: false,
@@ -363,20 +367,23 @@ function yearMonthAmend(options) {
     ObjectAssign(options, dateStyleHacks[style]);
   }
   if (!('year' in options || 'month' in options || 'era' in options)) {
-    options = ObjectAssign(options, { year: 'numeric', month: 'numeric' });
+    if (hasAnyDateTimeOptions(originalOptions)) {
+      throw new TypeError(`cannot format PlainYearMonth with options [${ObjectKeys(originalOptions)}]`);
+    }
+    ObjectAssign(options, { year: 'numeric', month: 'numeric' });
   }
   return options;
 }
 
-function monthDayAmend(options) {
+function monthDayAmend(originalOptions) {
   // Try to fake what dateStyle should do for dates without a day
   const dateStyleHacks = {
     short: { month: 'numeric', day: 'numeric' },
     medium: { month: 'short', day: 'numeric' },
     long: { month: 'long', day: 'numeric' },
     full: { month: 'long', day: 'numeric' }
   };
-  options = amend(options, {
+  const options = amend(originalOptions, {
     year: false,
     hour: false,
     minute: false,
@@ -392,13 +399,16 @@ function monthDayAmend(options) {
     ObjectAssign(options, dateStyleHacks[style]);
   }
   if (!('month' in options || 'day' in options)) {
-    options = ObjectAssign({}, options, { month: 'numeric', day: 'numeric' });
+    if (hasAnyDateTimeOptions(originalOptions)) {
+      throw new TypeError(`cannot format PlainMonthDay with options [${ObjectKeys(originalOptions)}]`);
+    }
+    ObjectAssign(options, { month: 'numeric', day: 'numeric' });
   }
   return options;
 }
 
-function dateAmend(options) {
-  options = amend(options, {
+function dateAmend(originalOptions) {
+  const options = amend(originalOptions, {
     hour: false,
     minute: false,
     second: false,
@@ -407,7 +417,10 @@ function dateAmend(options) {
     timeStyle: false
   });
   if (!hasDateOptions(options)) {
-    options = ObjectAssign({}, options, {
+    if (hasAnyDateTimeOptions(originalOptions)) {
+      throw new TypeError(`cannot format PlainDate with options [${ObjectKeys(originalOptions)}]`);
+    }
+    ObjectAssign(options, {
       year: 'numeric',
       month: 'numeric',
       day: 'numeric'
@@ -416,10 +429,13 @@ function dateAmend(options) {
   return options;
 }
 
-function datetimeAmend(options) {
-  options = amend(options, { timeZoneName: false });
+function datetimeAmend(originalOptions) {
+  const options = amend(originalOptions, { timeZoneName: false });
   if (!hasTimeOptions(options) && !hasDateOptions(options)) {
-    options = ObjectAssign({}, options, {
+    if (hasAnyDateTimeOptions(originalOptions)) {
+      throw new TypeError(`cannot format PlainDateTime with options [${ObjectKeys(originalOptions)}]`);
+    }
+    ObjectAssign(options, {
       year: 'numeric',
       month: 'numeric',
       day: 'numeric',
@@ -467,6 +483,16 @@ function hasTimeOptions(options) {
   );
 }
 
+function hasAnyDateTimeOptions(originalOptions) {
+  return (
+    hasDateOptions(originalOptions) ||
+    hasTimeOptions(originalOptions) ||
+    'dateStyle' in originalOptions ||
+    'timeStyle' in originalOptions ||
+    'timeZoneName' in originalOptions
+  );
+}
+
 function isTemporalObject(obj) {
   return (
     ES.IsTemporalDate(obj) ||

diff --git a/polyfill/lib/primordials.mjs b/polyfill/lib/primordials.mjs
@@ -34,7 +34,8 @@ export const {
   getOwnPropertyNames: ObjectGetOwnPropertyNames,
   defineProperty: ObjectDefineProperty,
   defineProperties: ObjectDefineProperties,
-  entries: ObjectEntries
+  entries: ObjectEntries,
+  keys: ObjectKeys
 } = Object;
 
 export const {

diff --git a/spec/intl.html b/spec/intl.html
@@ -855,11 +855,14 @@ <h1>
             1. If _required_ is ~time~ or ~any~, then
               1. Set _formatOptions_.[[hourCycle]] to _options_.[[hourCycle]].
           1. Let _needDefaults_ be *true*.
+          1. Let _anyPresent_ be *false*.
           1. For each property name _prop_ of _requiredOptions_, do
             1. Let _value_ be _options_.[[&lt;_prop_>]].
             1. If _value_ is not *undefined*, then
               1. Set _formatOptions_.[[&lt;_prop_>]] to _value_.
               1. Set _needDefaults_ to *false*.
+              1. Set _anyPresent_ to *true*.
+          1. If _anyPresent_ is *false*, return *null*.
           1. If _needDefaults_ is *true*, then
             1. For each property name _prop_ of _defaultOptions_, do
               1. Set _formatOptions_.[[&lt;_prop_>]] to *"numeric"*.