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

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

@@ -23,6 +23,17 @@ void PlainTimePrototype::initialize(GlobalObject& global_object)
 
     // 4.3.2 Temporal.PlainTime.prototype[ @@toStringTag ], https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype-@@tostringtag
     define_direct_property(*vm.well_known_symbol_to_string_tag(), js_string(vm.heap(), "Temporal.PlainTime"), Attribute::Configurable);
+
+    u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(vm.names.valueOf, value_of, 0, attr);
+}
+
+// 4.3.23 Temporal.PlainTime.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype.valueof
+JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::value_of)
+{
+    // 1. Throw a TypeError exception.
+    vm.throw_exception<TypeError>(global_object, ErrorType::Convert, "Temporal.PlainTime", "a primitive value");
+    return {};
 }
 
 }

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

@@ -17,6 +17,9 @@ public:
     explicit PlainTimePrototype(GlobalObject&);
     virtual void initialize(GlobalObject&) override;
     virtual ~PlainTimePrototype() override = default;
+
+private:
+    JS_DECLARE_NATIVE_FUNCTION(value_of);
 };
 
 }

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

@@ -0,0 +1,7 @@
+test("errors", () => {
+    test("throws TypeError", () => {
+        expect(() => {
+            new Temporal.PlainTime(19, 54, 38).valueOf();
+        }).toThrowWithMessage(TypeError, "Cannot convert Temporal.PlainTime to a primitive value");
+    });
+});