LibJS: Implement Temporal.PlainTime.from()

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

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/TypeCasts.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Temporal/AbstractOperations.h>
 #include <LibJS/Runtime/Temporal/PlainTime.h>
@@ -26,6 +27,9 @@ void PlainTimeConstructor::initialize(GlobalObject& global_object)
     // 4.2.1 Temporal.PlainTime.prototype, https://tc39.es/proposal-temporal/#sec-temporal-plaintime-prototype
     define_direct_property(vm.names.prototype, global_object.temporal_plain_time_prototype(), 0);
 
+    u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(vm.names.from, from, 1, attr);
+
     define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
 }
 
@@ -88,4 +92,30 @@ Value PlainTimeConstructor::construct(FunctionObject& new_target)
     return create_temporal_time(global_object, hour, minute, second, millisecond, microsecond, nanosecond, &new_target);
 }
 
+// 4.2.2 Temporal.PlainTime.from ( item [ , options ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime.from
+JS_DEFINE_NATIVE_FUNCTION(PlainTimeConstructor::from)
+{
+    // 1. Set options to ? GetOptionsObject(options).
+    auto* options = get_options_object(global_object, vm.argument(1));
+    if (vm.exception())
+        return {};
+
+    // 2. Let overflow be ? ToTemporalOverflow(options).
+    auto overflow = to_temporal_overflow(global_object, *options);
+    if (vm.exception())
+        return {};
+
+    auto item = vm.argument(0);
+
+    // 3. If Type(item) is Object and item has an [[InitializedTemporalTime]] internal slot, then
+    if (item.is_object() && is<PlainTime>(item.as_object())) {
+        auto& plain_time = static_cast<PlainTime&>(item.as_object());
+        // a. Return ? CreateTemporalTime(item.[[ISOHour]], item.[[ISOMinute]], item.[[ISOSecond]], item.[[ISOMillisecond]], item.[[ISOMicrosecond]], item.[[ISONanosecond]]).
+        return create_temporal_time(global_object, plain_time.iso_hour(), plain_time.iso_minute(), plain_time.iso_second(), plain_time.iso_millisecond(), plain_time.iso_microsecond(), plain_time.iso_nanosecond());
+    }
+
+    // 4. Return ? ToTemporalTime(item, overflow).
+    return to_temporal_time(global_object, item, *overflow);
+}
+
 }

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

@@ -23,6 +23,8 @@ public:
 
 private:
     virtual bool has_constructor() const override { return true; }
+
+    JS_DECLARE_NATIVE_FUNCTION(from);
 };
 
 }

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainTime/PlainTime.from.js

@@ -0,0 +1,50 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainTime.from).toHaveLength(1);
+    });
+
+    test("PlainTime instance argument", () => {
+        const plainTime = new Temporal.PlainTime(18, 45, 37, 1, 2, 3);
+        const createdPlainTime = Temporal.PlainTime.from(plainTime);
+        expect(createdPlainTime.hour).toBe(18);
+        expect(createdPlainTime.minute).toBe(45);
+        expect(createdPlainTime.second).toBe(37);
+        expect(createdPlainTime.millisecond).toBe(1);
+        expect(createdPlainTime.microsecond).toBe(2);
+        expect(createdPlainTime.nanosecond).toBe(3);
+    });
+
+    test("PlainDateTime instance argument", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 8, 27, 18, 45, 37, 1, 2, 3);
+        const createdPlainTime = Temporal.PlainTime.from(plainDateTime);
+        expect(createdPlainTime.hour).toBe(18);
+        expect(createdPlainTime.minute).toBe(45);
+        expect(createdPlainTime.second).toBe(37);
+        expect(createdPlainTime.millisecond).toBe(1);
+        expect(createdPlainTime.microsecond).toBe(2);
+        expect(createdPlainTime.nanosecond).toBe(3);
+    });
+
+    test("ZonedDateTime instance argument", () => {
+        const timeZone = new Temporal.TimeZone("UTC");
+        const zonedDateTime = new Temporal.ZonedDateTime(1627318123456789000n, timeZone);
+        const createdPlainTime = Temporal.PlainTime.from(zonedDateTime);
+        expect(createdPlainTime.hour).toBe(16);
+        expect(createdPlainTime.minute).toBe(48);
+        expect(createdPlainTime.second).toBe(43);
+        expect(createdPlainTime.millisecond).toBe(456);
+        expect(createdPlainTime.microsecond).toBe(789);
+        expect(createdPlainTime.nanosecond).toBe(0);
+    });
+
+    // Un-skip once ParseISODateTime & ParseTemporalTimeString are implemented
+    test.skip("PlainTime string argument", () => {
+        const createdPlainTime = Temporal.PlainTime.from("2021-08-27T18:44:11Z");
+        expect(createdPlainTime.hour).toBe(18);
+        expect(createdPlainTime.minute).toBe(44);
+        expect(createdPlainTime.second).toBe(11);
+        expect(createdPlainTime.millisecond).toBe(0);
+        expect(createdPlainTime.microsecond).toBe(0);
+        expect(createdPlainTime.nanosecond).toBe(0);
+    });
+});