LibJS: Implement Temporal.ZonedDateTime.prototype.equals

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

@@ -646,4 +646,25 @@ ThrowCompletionOr<MarkedValueList> get_possible_instants_for(GlobalObject& globa
     return { move(list) };
 }
 
+// 11.6.18 TimeZoneEquals ( one, two ), https://tc39.es/proposal-temporal/#sec-temporal-timezoneequals
+ThrowCompletionOr<bool> time_zone_equals(GlobalObject& global_object, Object& one, Object& two)
+{
+    // 1. If one and two are the same Object value, return true.
+    if (&one == &two)
+        return true;
+
+    // 2. Let timeZoneOne be ? ToString(one).
+    auto time_zone_one = TRY(Value(&one).to_string(global_object));
+
+    // 3. Let timeZoneTwo be ? ToString(two).
+    auto time_zone_two = TRY(Value(&two).to_string(global_object));
+
+    // 4. If timeZoneOne is timeZoneTwo, return true.
+    if (time_zone_one == time_zone_two)
+        return true;
+
+    // 5. Return false.
+    return false;
+}
+
 }

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

@@ -53,6 +53,7 @@ ThrowCompletionOr<PlainDateTime*> builtin_time_zone_get_plain_date_time_for(Glob
 ThrowCompletionOr<Instant*> builtin_time_zone_get_instant_for(GlobalObject&, Value time_zone, PlainDateTime&, StringView disambiguation);
 ThrowCompletionOr<Instant*> disambiguate_possible_instants(GlobalObject&, Vector<Value> const& possible_instants, Value time_zone, PlainDateTime&, StringView disambiguation);
 ThrowCompletionOr<MarkedValueList> get_possible_instants_for(GlobalObject&, Value time_zone, PlainDateTime&);
+ThrowCompletionOr<bool> time_zone_equals(GlobalObject&, Object& one, Object& two);
 
 bool is_valid_time_zone_numeric_utc_offset_syntax(String const&);
 

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

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -68,6 +69,7 @@ void ZonedDateTimePrototype::initialize(GlobalObject& global_object)
     define_native_function(vm.names.withPlainDate, with_plain_date, 1, attr);
     define_native_function(vm.names.withTimeZone, with_time_zone, 1, attr);
     define_native_function(vm.names.withCalendar, with_calendar, 1, attr);
+    define_native_function(vm.names.equals, equals, 1, attr);
     define_native_function(vm.names.valueOf, value_of, 0, attr);
     define_native_function(vm.names.startOfDay, start_of_day, 0, attr);
     define_native_function(vm.names.toInstant, to_instant, 0, attr);
@@ -808,6 +810,28 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::with_calendar)
     return MUST(create_temporal_zoned_date_time(global_object, zoned_date_time->nanoseconds(), zoned_date_time->time_zone(), *calendar));
 }
 
+// 6.3.40 Temporal.ZonedDateTime.prototype.equals ( other ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime.prototype.equals
+JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::equals)
+{
+    // 1. Let zonedDateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(zonedDateTime, [[InitializedTemporalZonedDateTime]]).
+    auto* zoned_date_time = TRY(typed_this_object(global_object));
+
+    // 3. Set other to ? ToTemporalZonedDateTime(other).
+    auto* other = TRY(to_temporal_zoned_date_time(global_object, vm.argument(0)));
+
+    // 4. If zonedDateTime.[[Nanoseconds]] ≠ other.[[Nanoseconds]], return false.
+    if (zoned_date_time->nanoseconds().big_integer() != other->nanoseconds().big_integer())
+        return Value(false);
+
+    // 5. If ? TimeZoneEquals(zonedDateTime.[[TimeZone]], other.[[TimeZone]]) is false, return false.
+    if (!TRY(time_zone_equals(global_object, zoned_date_time->time_zone(), other->time_zone())))
+        return Value(false);
+
+    // 6. Return ? CalendarEquals(zonedDateTime.[[Calendar]], other.[[Calendar]]).
+    return Value(TRY(calendar_equals(global_object, zoned_date_time->calendar(), other->calendar())));
+}
+
 // 6.3.44 Temporal.ZonedDateTime.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime.prototype.valueof
 JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::value_of)
 {

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

@@ -53,6 +53,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(with_plain_date);
     JS_DECLARE_NATIVE_FUNCTION(with_time_zone);
     JS_DECLARE_NATIVE_FUNCTION(with_calendar);
+    JS_DECLARE_NATIVE_FUNCTION(equals);
     JS_DECLARE_NATIVE_FUNCTION(value_of);
     JS_DECLARE_NATIVE_FUNCTION(start_of_day);
     JS_DECLARE_NATIVE_FUNCTION(to_instant);

Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.equals.js

@@ -0,0 +1,23 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.ZonedDateTime.prototype.equals).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const zonedDateTimeOne = new Temporal.ZonedDateTime(1n, new Temporal.TimeZone("UTC"));
+        const zonedDateTimeTwo = new Temporal.ZonedDateTime(2n, new Temporal.TimeZone("UTC"));
+
+        expect(zonedDateTimeOne.equals(zonedDateTimeOne)).toBeTrue();
+        expect(zonedDateTimeTwo.equals(zonedDateTimeTwo)).toBeTrue();
+        expect(zonedDateTimeOne.equals(zonedDateTimeTwo)).toBeFalse();
+        expect(zonedDateTimeTwo.equals(zonedDateTimeOne)).toBeFalse();
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.ZonedDateTime object", () => {
+        expect(() => {
+            Temporal.ZonedDateTime.prototype.equals.call("foo");
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.ZonedDateTime");
+    });
+});