LibJS: Implement Temporal.Duration.prototype.weeks

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/23d0c3494fa
Pull-request: https://github.com/SerenityOS/serenity/pull/8794
Reviewed-by: https://github.com/IdanHo ✅

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -353,6 +353,7 @@ namespace JS {
     P(valueOf)                               \
     P(values)                                \
     P(warn)                                  \
+    P(weeks)                                 \
     P(writable)                              \
     P(years)
 

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

@@ -27,6 +27,7 @@ void DurationPrototype::initialize(GlobalObject& global_object)
 
     define_native_accessor(vm.names.years, years_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.months, months_getter, {}, Attribute::Configurable);
+    define_native_accessor(vm.names.weeks, weeks_getter, {}, Attribute::Configurable);
 }
 
 static Duration* typed_this(GlobalObject& global_object)
@@ -68,4 +69,17 @@ JS_DEFINE_NATIVE_FUNCTION(DurationPrototype::months_getter)
     return Value(duration->months());
 }
 
+// 7.3.5 get Temporal.Duration.prototype.weeks, https://tc39.es/proposal-temporal/#sec-get-temporal.duration.prototype.weeks
+JS_DEFINE_NATIVE_FUNCTION(DurationPrototype::weeks_getter)
+{
+    // 1. Let duration be the this value.
+    // 2. Perform ? RequireInternalSlot(duration, [[InitializedTemporalDuration]]).
+    auto* duration = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Return duration.[[Weeks]].
+    return Value(duration->weeks());
+}
+
 }

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

@@ -21,6 +21,7 @@ public:
 private:
     JS_DECLARE_NATIVE_FUNCTION(years_getter);
     JS_DECLARE_NATIVE_FUNCTION(months_getter);
+    JS_DECLARE_NATIVE_FUNCTION(weeks_getter);
 };
 
 }

Userland/Libraries/LibJS/Tests/builtins/Temporal/Duration/Duration.prototype.weeks.js

@@ -0,0 +1,14 @@
+describe("correct behavior", () => {
+    test("basic functionality", () => {
+        const duration = new Temporal.Duration(0, 0, 123);
+        expect(duration.weeks).toBe(123);
+    });
+});
+
+test("errors", () => {
+    test("this value must be a Temporal.Duration object", () => {
+        expect(() => {
+            Reflect.get(Temporal.Duration.prototype, "weeks", "foo");
+        }).toThrowWithMessage(TypeError, "Not a Temporal.Duration");
+    });
+});