LibJS: Implement Temporal.PlainTime.prototype.second

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -308,6 +308,7 @@ namespace JS {
     P(revoke)                                \
     P(round)                                 \
     P(seal)                                  \
+    P(second)                                \
     P(seconds)                               \
     P(set)                                   \
     P(setBigInt64)                           \

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

@@ -29,6 +29,7 @@ void PlainTimePrototype::initialize(GlobalObject& global_object)
     define_native_accessor(vm.names.calendar, calendar_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.hour, hour_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.minute, minute_getter, {}, Attribute::Configurable);
+    define_native_accessor(vm.names.second, second_getter, {}, Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(vm.names.valueOf, value_of, 0, attr);
@@ -86,6 +87,19 @@ JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::minute_getter)
     return Value(temporal_time->iso_minute());
 }
 
+// 4.3.6 get Temporal.PlainTime.prototype.second, https://tc39.es/proposal-temporal/#sec-get-temporal.plaintime.prototype.second
+JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::second_getter)
+{
+    // 1. Let temporalTime be the this value.
+    // 2. Perform ? RequireInternalSlot(temporalTime, [[InitializedTemporalTime]]).
+    auto* temporal_time = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Return 𝔽(temporalTime.[[ISOSecond]]).
+    return Value(temporal_time->iso_second());
+}
+
 // 4.3.23 Temporal.PlainTime.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype.valueof
 JS_DEFINE_NATIVE_FUNCTION(PlainTimePrototype::value_of)
 {

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

@@ -22,6 +22,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(calendar_getter);
     JS_DECLARE_NATIVE_FUNCTION(hour_getter);
     JS_DECLARE_NATIVE_FUNCTION(minute_getter);
+    JS_DECLARE_NATIVE_FUNCTION(second_getter);
     JS_DECLARE_NATIVE_FUNCTION(value_of);
 };
 

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

@@ -0,0 +1,14 @@
+describe("correct behavior", () => {
+    test("basic functionality", () => {
+        const plainTime = new Temporal.PlainTime(0, 0, 12);
+        expect(plainTime.second).toBe(12);
+    });
+});
+
+test("errors", () => {
+    test("this value must be a Temporal.PlainTime object", () => {
+        expect(() => {
+            Reflect.get(Temporal.PlainTime.prototype, "second", "foo");
+        }).toThrowWithMessage(TypeError, "Not a Temporal.PlainTime");
+    });
+});