LibJS: Start implementing Temporal.PlainTime

This commit adds the PlainTime object itself, its constructor and
prototype (currently empty), and the CreateTemporalTime abstract
operation.

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

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/Temporal/PlainTime.h>
+#include <LibJS/Runtime/Temporal/PlainTimeConstructor.h>
+
+namespace JS::Temporal {
+
+// 4.1 The Temporal.PlainTime Constructor, https://tc39.es/proposal-temporal/#sec-temporal-plaintime-constructor
+PlainTimeConstructor::PlainTimeConstructor(GlobalObject& global_object)
+    : NativeFunction(vm().names.PlainTime.as_string(), *global_object.function_prototype())
+{
+}
+
+void PlainTimeConstructor::initialize(GlobalObject& global_object)
+{
+    NativeFunction::initialize(global_object);
+
+    auto& vm = this->vm();
+
+    // 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);
+
+    define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
+}
+
+// 4.1.1 Temporal.PlainTime ( [ hour [ , minute [ , second [ , millisecond [ , microsecond [ , nanosecond ] ] ] ] ] ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime
+Value PlainTimeConstructor::call()
+{
+    auto& vm = this->vm();
+
+    // 1. If NewTarget is undefined, throw a TypeError exception.
+    vm.throw_exception<TypeError>(global_object(), ErrorType::ConstructorWithoutNew, "Temporal.PlainTime");
+    return {};
+}
+
+// 4.1.1 Temporal.PlainTime ( [ hour [ , minute [ , second [ , millisecond [ , microsecond [ , nanosecond ] ] ] ] ] ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaintime
+Value PlainTimeConstructor::construct(FunctionObject& new_target)
+{
+    auto& vm = this->vm();
+    auto& global_object = this->global_object();
+
+    // 2. Let hour be ? ToIntegerOrInfinity(hour).
+    auto hour = vm.argument(0).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. If hour is +∞ or -∞, throw a RangeError exception.
+    if (Value(hour).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 4. Let minute be ? ToIntegerOrInfinity(hour).
+    auto minute = vm.argument(1).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 5. If minute is +∞ or -∞, throw a RangeError exception.
+    if (Value(minute).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 6. Let second be ? ToIntegerOrInfinity(hour).
+    auto second = vm.argument(2).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 7. If second is +∞ or -∞, throw a RangeError exception.
+    if (Value(second).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 8. Let millisecond be ? ToIntegerOrInfinity(hour).
+    auto millisecond = vm.argument(3).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 9. If millisecond is +∞ or -∞, throw a RangeError exception.
+    if (Value(millisecond).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 10. Let microsecond be ? ToIntegerOrInfinity(hour).
+    auto microsecond = vm.argument(4).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 11. If microsecond is +∞ or -∞, throw a RangeError exception.
+    if (Value(microsecond).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 12. Let nanosecond be ? ToIntegerOrInfinity(hour).
+    auto nanosecond = vm.argument(5).to_integer_or_infinity(global_object);
+    if (vm.exception())
+        return {};
+
+    // 13. If nanosecond is +∞ or -∞, throw a RangeError exception.
+    if (Value(nanosecond).is_infinity()) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // IMPLEMENTATION DEFINED: This is an optimization that allows us to treat these doubles as normal integers from this point onwards.
+    // This does not change the exposed behaviour as the call to CreateTemporalTime will immediately check that these values are valid
+    // ISO values (for hours: 0 - 23, for minutes and seconds: 0 - 59, milliseconds, microseconds, and nanoseconds: 0 - 999) all of which
+    // are subsets of this check.
+    if (!AK::is_within_range<u8>(hour) || !AK::is_within_range<u8>(minute) || !AK::is_within_range<u8>(second) || !AK::is_within_range<u16>(millisecond) || !AK::is_within_range<u16>(microsecond) || !AK::is_within_range<u16>(nanosecond)) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidPlainTime);
+        return {};
+    }
+
+    // 14. Return ? CreateTemporalTime(hour, minute, second, millisecond, microsecond, nanosecond, NewTarget).
+    return create_temporal_time(global_object, hour, minute, second, millisecond, microsecond, nanosecond, &new_target);
+}
+
+}