Temporal: Adjust and expand tests for observable calls to ToString(calendar)

This implements the normative change in
tc39/proposal-temporal#2269 which reached
consensus at the July 2022 TC39 meeting.

There was already a test for PlainDate for this topic, which needs to be
adjusted to accommodate the normative change. Tests for PlainDateTime and
ZonedDateTime did not yet exist, so add new ones based on the PlainDate
test.

Author: ptomato

test/built-ins/Temporal/PlainDate/prototype/toString/calendar-tostring.js

@@ -3,7 +3,7 @@
 
 /*---
 esid: sec-temporal.plaindate.protoype.tostring
-description: Should always call 'toString' on the calendar once.
+description: Should call 'toString' on the calendar once unless calendarName == 'never'.
 features: [Temporal]
 ---*/
 
@@ -16,13 +16,13 @@ const customCalendar = {
 };
 const date = new Temporal.PlainDate(2000, 5, 2, customCalendar);
 [
-  ["always", "2000-05-02[u-ca=custom]"],
-  ["auto", "2000-05-02[u-ca=custom]"],
-  ["never", "2000-05-02"],
-  [undefined, "2000-05-02[u-ca=custom]"],
-].forEach(([calendarName, expected]) => {
+  ["always", "2000-05-02[u-ca=custom]", 1],
+  ["auto", "2000-05-02[u-ca=custom]", 1],
+  ["never", "2000-05-02", 0],
+  [undefined, "2000-05-02[u-ca=custom]", 1],
+].forEach(([calendarName, expectedResult, expectedCalls]) => {
   calls = 0;
   const result = date.toString({ calendarName });
-  assert.sameValue(result, expected, `calendarName = ${calendarName}: expected ${expected}`);
-  assert.sameValue(calls, 1, `calendarName = ${calendarName}: expected one call to 'toString'`);
+  assert.sameValue(result, expectedResult, `calendarName = ${calendarName}: expected ${expectedResult}`);
+  assert.sameValue(calls, expectedCalls, `calendarName = ${calendarName}: expected ${expectedCalls} call(s) to 'toString'`);
 });

test/built-ins/Temporal/PlainDateTime/prototype/toString/calendar-tostring.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.protoype.tostring
+description: Should call 'toString' on the calendar once unless calendarName == 'never'.
+features: [Temporal]
+---*/
+
+let calls;
+const customCalendar = {
+  toString() {
+    ++calls;
+    return "custom";
+  }
+};
+const date = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321, customCalendar);
+[
+  ["always", "2000-05-02T12:34:56.987654321[u-ca=custom]", 1],
+  ["auto", "2000-05-02T12:34:56.987654321[u-ca=custom]", 1],
+  ["never", "2000-05-02T12:34:56.987654321", 0],
+  [undefined, "2000-05-02T12:34:56.987654321[u-ca=custom]", 1],
+].forEach(([calendarName, expectedResult, expectedCalls]) => {
+  calls = 0;
+  const result = date.toString({ calendarName });
+  assert.sameValue(result, expectedResult, `calendarName = ${calendarName}: expected ${expectedResult}`);
+  assert.sameValue(calls, expectedCalls, `calendarName = ${calendarName}: expected ${expectedCalls} call(s) to 'toString'`);
+});

test/built-ins/Temporal/ZonedDateTime/prototype/toString/calendar-tostring.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.protoype.tostring
+description: Should call 'toString' on the calendar once unless calendarName == 'never'.
+features: [Temporal]
+---*/
+
+let calls;
+const customCalendar = {
+  toString() {
+    ++calls;
+    return "custom";
+  }
+};
+const date = new Temporal.ZonedDateTime(3661_987_654_321n, "UTC", customCalendar);
+[
+  ["always", "1970-01-01T01:01:01.987654321+00:00[UTC][u-ca=custom]", 1],
+  ["auto", "1970-01-01T01:01:01.987654321+00:00[UTC][u-ca=custom]", 1],
+  ["never", "1970-01-01T01:01:01.987654321+00:00[UTC]", 0],
+  [undefined, "1970-01-01T01:01:01.987654321+00:00[UTC][u-ca=custom]", 1],
+].forEach(([calendarName, expectedResult, expectedCalls]) => {
+  calls = 0;
+  const result = date.toString({ calendarName });
+  assert.sameValue(result, expectedResult, `calendarName = ${calendarName}: expected ${expectedResult}`);
+  assert.sameValue(calls, expectedCalls, `calendarName = ${calendarName}: expected ${expectedCalls} call(s) to 'toString'`);
+});