Change Temporal.TimeZone compare semantics to use .id

Compare semantics for custom time zones that _don't_ extend
Temporal.TimeZone (and therefore don't have the internal slot) use the
value of the .id property, instead of calling toString().

Normative PR: https://github.com/tc39/proposal-temporal/pull/2482

harness/temporalHelpers.js

@@ -1798,6 +1798,10 @@ var TemporalHelpers = {
         return null;
       }
 
+      get id() {
+        return "Custom/Spring_Fall";
+      }
+
       toString() {
         return "Custom/Spring_Fall";
       }
@@ -1818,7 +1822,9 @@ var TemporalHelpers = {
    */
   timeZoneObserver(calls, objectName, methodOverrides = {}) {
     const utc = new Temporal.TimeZone("UTC");
-    const trackingMethods = {};
+    const trackingMethods = {
+      id: "UTC",
+    };
     // Automatically generate the methods
     ["getOffsetNanosecondsFor", "getPossibleInstantsFor", "toString"].forEach((methodName) => {
       trackingMethods[methodName] = function (...args) {

test/built-ins/Temporal/ZonedDateTime/prototype/equals/order-of-operations.js

@@ -58,12 +58,8 @@ const expected = [
   "get other.timeZone.getOffsetNanosecondsFor",
   "call other.timeZone.getOffsetNanosecondsFor",
   // TimeZoneEquals
-  "get this.timeZone[Symbol.toPrimitive]",
+  "get this.timeZone.id",
-  "get this.timeZone.toString",
+  "get other.timeZone.id",
-  "call this.timeZone.toString",
-  "get other.timeZone[Symbol.toPrimitive]",
-  "get other.timeZone.toString",
-  "call other.timeZone.toString",
   // CalendarEquals
   "get this.calendar.id",
   "get other.calendar.id",

test/built-ins/Temporal/ZonedDateTime/prototype/since/order-of-operations.js

@@ -125,12 +125,8 @@ actual.splice(0); // clear
 // Making largestUnit a calendar unit adds the following observable operations:
 const expectedOpsForCalendarDifference = [
   // TimeZoneEquals
-  "get this.timeZone[Symbol.toPrimitive]",
+  "get this.timeZone.id",
-  "get this.timeZone.toString",
+  "get other.timeZone.id",
-  "call this.timeZone.toString",
-  "get other.timeZone[Symbol.toPrimitive]",
-  "get other.timeZone.toString",
-  "call other.timeZone.toString",
   // DifferenceZonedDateTime
   "get this.timeZone.getOffsetNanosecondsFor",
   "call this.timeZone.getOffsetNanosecondsFor",

test/built-ins/Temporal/ZonedDateTime/prototype/toString/order-of-operations.js

@@ -31,9 +31,7 @@ const expected = [
   "call this.timeZone.getOffsetNanosecondsFor",
   "get this.timeZone.getOffsetNanosecondsFor",
   "call this.timeZone.getOffsetNanosecondsFor",
-  "get this.timeZone[Symbol.toPrimitive]",
+  "get this.timeZone.id",
-  "get this.timeZone.toString",
-  "call this.timeZone.toString",
   "get this.calendar.id",
 ];
 const actual = [];
@@ -79,9 +77,7 @@ const expectedForFractionalSecondDigits = [
   "call this.timeZone.getOffsetNanosecondsFor",
   "get this.timeZone.getOffsetNanosecondsFor",
   "call this.timeZone.getOffsetNanosecondsFor",
-  "get this.timeZone[Symbol.toPrimitive]",
+  "get this.timeZone.id",
-  "get this.timeZone.toString",
-  "call this.timeZone.toString",
   "get this.calendar.id",
 ];
 

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-auto.js

@@ -12,7 +12,7 @@ const tests = [
   ["+01:00", "1970-01-01T02:01:01.987654321+01:00[+01:00]", "built-in offset"],
   [{
     getOffsetNanosecondsFor() { return 0; },
-    toString() { return "Etc/Custom"; },
+    id: "Etc/Custom",
   }, "1970-01-01T01:01:01.987654321+00:00[Etc/Custom]", "custom"],
 ];
 

test/built-ins/Temporal/ZonedDateTime/prototype/toString/timezonename-critical.js

@@ -14,7 +14,7 @@ const tests = [
   ["+01:00", "1970-01-01T02:01:01.987654321+01:00[!+01:00]", "built-in offset"],
   [{
     getOffsetNanosecondsFor() { return 0; },
-    toString() { return "Etc/Custom"; },
+    id: "Etc/Custom",
   }, "1970-01-01T01:01:01.987654321+00:00[!Etc/Custom]", "custom"],
 ];
 

test/built-ins/Temporal/ZonedDateTime/prototype/until/order-of-operations.js

@@ -125,12 +125,8 @@ actual.splice(0); // clear
 // Making largestUnit a calendar unit adds the following observable operations:
 const expectedOpsForCalendarDifference = [
   // TimeZoneEquals
-  "get this.timeZone[Symbol.toPrimitive]",
+  "get this.timeZone.id",
-  "get this.timeZone.toString",
+  "get other.timeZone.id",
-  "call this.timeZone.toString",
-  "get other.timeZone[Symbol.toPrimitive]",
-  "get other.timeZone.toString",
-  "call other.timeZone.toString",
   // DifferenceZonedDateTime
   "get this.timeZone.getOffsetNanosecondsFor",
   "call this.timeZone.getOffsetNanosecondsFor",

test/staging/Temporal/UserTimezone/old/trivial-protocol.js

@@ -18,9 +18,7 @@ var obj = {
     var epochNs = MakeDate(dayNum, time);
     return [new Temporal.Instant(epochNs)];
   },
-  toString() {
+  id: "Etc/Custom/UTC_Protocol",
-    return "Etc/Custom/UTC_Protocol";
-  }
 };
 var inst = Temporal.Instant.fromEpochNanoseconds(0n);
 

test/staging/Temporal/ZonedDateTime/old/construction-and-properties.js

@@ -19,7 +19,7 @@ assert.sameValue(zdt.toInstant().epochSeconds, Math.floor(Date.UTC(1976, 10, 18,
 assert.sameValue(zdt.toInstant().epochMilliseconds, Date.UTC(1976, 10, 18, 15, 23, 30, 123), "epochMilliseconds");
 
 // Temporal.ZonedDateTime for (1976, 11, 18, 15, 23, 30, 123, 456, 789)"
-  var zdt = new Temporal.ZonedDateTime(epochNanos, new Temporal.TimeZone("UTC"));
+  var zdt = new Temporal.ZonedDateTime(epochNanos, "UTC");
 // can be constructed
 assert(zdt instanceof Temporal.ZonedDateTime);
 assert.sameValue(typeof zdt, "object");
@@ -70,7 +70,7 @@ var fakeGregorian = {
 };
 var fakeVienna = {
   getOffsetNanosecondsFor() { return 3600_000_000_000; },
-  toString() { return "Europe/Vienna"; },
+  id: "Europe/Vienna",
 }
 var zdt = new Temporal.ZonedDateTime(epochNanos, fakeVienna, fakeGregorian);
 assert(zdt instanceof Temporal.ZonedDateTime);

test/staging/Temporal/ZonedDateTime/old/equals.js

@@ -9,7 +9,7 @@ features: [Temporal]
 
 var tz = {
   getPossibleInstantsFor(pdt) { return Temporal.TimeZone.from("-05:00").getPossibleInstantsFor(pdt); },
-  toString() { return "America/New_York"; },
+  id: "America/New_York",
 };
 var cal = {
   dateFromFields(...args) { return Temporal.Calendar.from("iso8601").dateFromFields(...args); },