LibJS: Implement Temporal.ZonedDateTime.prototype.valueOf()

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

@@ -56,6 +56,9 @@ void ZonedDateTimePrototype::initialize(GlobalObject& global_object)
     define_native_accessor(vm.names.inLeapYear, in_leap_year_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.offsetNanoseconds, offset_nanoseconds_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.offset, offset_getter, {}, Attribute::Configurable);
+
+    u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(vm.names.valueOf, value_of, 0, attr);
 }
 
 static ZonedDateTime* typed_this(GlobalObject& global_object)
@@ -691,4 +694,12 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::offset_getter)
     return js_string(vm, move(*offset_string));
 }
 
+// 6.3.44 Temporal.ZonedDateTime.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime.prototype.valueof
+JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::value_of)
+{
+    // 1. Throw a TypeError exception.
+    vm.throw_exception<TypeError>(global_object, ErrorType::Convert, "Temporal.ZonedDateTime", "a primitive value");
+    return {};
+}
+
 }

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

@@ -45,6 +45,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(in_leap_year_getter);
     JS_DECLARE_NATIVE_FUNCTION(offset_nanoseconds_getter);
     JS_DECLARE_NATIVE_FUNCTION(offset_getter);
+    JS_DECLARE_NATIVE_FUNCTION(value_of);
 };
 
 }

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

@@ -0,0 +1,11 @@
+test("errors", () => {
+    test("throws TypeError", () => {
+        const timeZone = new Temporal.TimeZone("UTC");
+        expect(() => {
+            new Temporal.ZonedDateTime(0n, timeZone).valueOf();
+        }).toThrowWithMessage(
+            TypeError,
+            "Cannot convert Temporal.ZonedDateTime to a primitive value"
+        );
+    });
+});