LibJS: Implement Temporal.PlainMonthDay.prototype.toLocaleString()

Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.cpp

@@ -34,6 +34,7 @@ void PlainMonthDayPrototype::initialize(GlobalObject& global_object)
 
  u8 attr = Attribute::Writable | Attribute::Configurable;
  define_native_function(vm.names.toString, to_string, 0, attr);
+ define_native_function(vm.names.toLocaleString, to_locale_string, 0, attr);
  define_native_function(vm.names.valueOf, value_of, 0, attr);
  define_native_function(vm.names.getISOFields, get_iso_fields, 0, attr);
 }
@@ -123,6 +124,24 @@ JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::to_string)
  return js_string(vm, *string);
 }
 
+// 10.3.9 Temporal.PlainMonthDay.prototype.toLocaleString ( [ locales [ , options ] ] ), https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.prototype.tolocalestring
+// NOTE: This is the minimum toLocaleString implementation for engines without ECMA-402.
+JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::to_locale_string)
+{
+ // 1. Let monthDay be the this value.
+ // 2. Perform ? RequireInternalSlot(monthDay, [[InitializedTemporalMonthDay]]).
+ auto* month_day = typed_this(global_object);
+ if (vm.exception())
+ return {};
+
+ // 3. Return ? TemporalMonthDayToString(monthDay, "auto").
+ auto string = temporal_month_day_to_string(global_object, *month_day, "auto"sv);
+ if (vm.exception())
+ return {};
+
+ return js_string(vm, *string);
+}
+
 // 10.3.11 Temporal.PlainMonthDay.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.prototype.valueof
 JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::value_of)
 {

Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.h

@@ -23,6 +23,7 @@ class PlainMonthDayPrototype final : public Object {
  JS_DECLARE_NATIVE_FUNCTION(month_code_getter);
  JS_DECLARE_NATIVE_FUNCTION(day_getter);
  JS_DECLARE_NATIVE_FUNCTION(to_string);
+ JS_DECLARE_NATIVE_FUNCTION(to_locale_string);
  JS_DECLARE_NATIVE_FUNCTION(value_of);
  JS_DECLARE_NATIVE_FUNCTION(get_iso_fields);
 };

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toLocaleString.js

@@ -0,0 +1,23 @@
+describe("correct behavior", () => {
+ test("length is 0", () => {
+ expect(Temporal.PlainMonthDay.prototype.toLocaleString).toHaveLength(0);
+ });
+
+ test("basic functionality", () => {
+ let plainMonthDay;
+
+ plainMonthDay = new Temporal.PlainMonthDay(7, 6);
+ expect(plainMonthDay.toLocaleString()).toBe("07-06");
+
+ plainMonthDay = new Temporal.PlainMonthDay(7, 6, { toString: () => "foo" }, 2021);
+ expect(plainMonthDay.toLocaleString()).toBe("2021-07-06[u-ca=foo]");
+ });
+});
+
+describe("errors", () => {
+ test("this value must be a Temporal.PlainMonthDay object", () => {
+ expect(() => {
+ Temporal.PlainMonthDay.prototype.toLocaleString.call("foo");
+ }).toThrowWithMessage(TypeError, "Not a Temporal.PlainMonthDay");
+ });
+});