Intl Era Monthcode: Tests for with() around Gregorian-like leap years

Adds tests for with() in the four calendars with Gregorian-like leap
years (buddhist, gregory, japanese, roc).

test/intl402/Temporal/PlainDate/prototype/with/leap-year-buddhist.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.with
+description: Check constraining days when year changes (buddhist calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "buddhist";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDate.from({ year: 2559, monthCode: "M02", day: 29, calendar }, options);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2555 }, options),
+  2555, 2, "M02", 29, "day not constrained when moving to another leap year",
+  "be", 2555);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2561 }),
+  2561, 2, "M02", 28, "day constrained when moving to a common year",
+  "be", 2561);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2561 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDate/prototype/with/leap-year-gregory.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.with
+description: Check constraining days when year changes (gregory calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "gregory";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDate.from({ year: 2016, monthCode: "M02", day: 29, calendar }, options);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2012 }, options),
+  2012, 2, "M02", 29, "day not constrained when moving to another leap year",
+  "ce", 2012);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2018 }),
+  2018, 2, "M02", 28, "day constrained when moving to a common year",
+  "ce", 2018);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDate/prototype/with/leap-year-japanese.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.with
+description: Check constraining days when year changes (japanese calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "japanese";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDate.from({ year: 2016, monthCode: "M02", day: 29, calendar }, options);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2012 }, options),
+  2012, 2, "M02", 29, "day not constrained when moving to another leap year",
+  "heisei", 24);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 2018 }),
+  2018, 2, "M02", 28, "day constrained when moving to a common year",
+  "heisei", 30);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDate/prototype/with/leap-year-roc.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.with
+description: Check constraining days when year changes (roc calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "roc";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDate.from({ year: 105, monthCode: "M02", day: 29, calendar }, options);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 101 }, options),
+  101, 2, "M02", 29, "day not constrained when moving to another leap year",
+  "roc", 101);
+
+TemporalHelpers.assertPlainDate(
+  leapDay.with({ year: 107 }),
+  107, 2, "M02", 28, "day constrained when moving to a common year",
+  "roc", 107);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 107 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDateTime/prototype/with/leap-year-buddhist.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.with
+description: Check constraining days when year changes (buddhist calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "buddhist";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDateTime.from({ year: 2559, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2555 }, options),
+  2555, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "be", 2555);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2561 }),
+  2561, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "be", 2561);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2561 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDateTime/prototype/with/leap-year-gregory.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.with
+description: Check constraining days when year changes (gregory calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "gregory";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDateTime.from({ year: 2016, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2012 }, options),
+  2012, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "ce", 2012);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2018 }),
+  2018, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "ce", 2018);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDateTime/prototype/with/leap-year-japanese.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.with
+description: Check constraining days when year changes (japanese calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "japanese";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDateTime.from({ year: 2016, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2012 }, options),
+  2012, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "heisei", 24);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2018 }),
+  2018, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "heisei", 30);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/PlainDateTime/prototype/with/leap-year-roc.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.with
+description: Check constraining days when year changes (roc calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "roc";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.PlainDateTime.from({ year: 105, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 101 }, options),
+  101, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "roc", 101);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 107 }),
+  107, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "roc", 107);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 107 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/ZonedDateTime/prototype/with/leap-year-buddhist.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.with
+description: Check constraining days when year changes (buddhist calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "buddhist";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.ZonedDateTime.from({ year: 2559, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2555 }, options).toPlainDateTime(),
+  2555, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "be", 2555);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2561 }).toPlainDateTime(),
+  2561, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "be", 2561);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2561 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/ZonedDateTime/prototype/with/leap-year-gregory.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.with
+description: Check constraining days when year changes (gregory calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "gregory";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.ZonedDateTime.from({ year: 2016, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2012 }, options).toPlainDateTime(),
+  2012, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "ce", 2012);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2018 }).toPlainDateTime(),
+  2018, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "ce", 2018);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/ZonedDateTime/prototype/with/leap-year-japanese.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.with
+description: Check constraining days when year changes (japanese calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "japanese";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.ZonedDateTime.from({ year: 2016, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2012 }, options).toPlainDateTime(),
+  2012, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "heisei", 24);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 2018 }).toPlainDateTime(),
+  2018, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "heisei", 30);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 2018 }, options);
+}, "reject when moving to a common year");

test/intl402/Temporal/ZonedDateTime/prototype/with/leap-year-roc.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.with
+description: Check constraining days when year changes (roc calendar)
+features: [Temporal, Intl.Era-monthcode]
+includes: [temporalHelpers.js]
+---*/
+
+const calendar = "roc";
+const options = { overflow: "reject" };
+
+const leapDay = Temporal.ZonedDateTime.from({ year: 105, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 101 }, options).toPlainDateTime(),
+  101, 2, "M02", 29,  12, 34, 0, 0, 0, 0,"day not constrained when moving to another leap year",
+  "roc", 101);
+
+TemporalHelpers.assertPlainDateTime(
+  leapDay.with({ year: 107 }).toPlainDateTime(),
+  107, 2, "M02", 28,  12, 34, 0, 0, 0, 0,"day constrained when moving to a common year",
+  "roc", 107);
+
+assert.throws(RangeError, function () {
+  leapDay.with({ year: 107 }, options);
+}, "reject when moving to a common year");