LibJS: Implement the Temporal.PlainMonthDay constructor

And the simple Temporal.PlainMonthDay.prototype getters, so that the constructed Temporal.PlainMonthDay may actually be validated.
Author: https://github.com/trflynn89 Commit: 1a386e78c3 Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2471
2025-07-29 20:29:18 +00:00 · 2024-11-20 12:59:15 -05:00 · 2024-11-20 12:59:15 -05:00 · 1a386e78c3 · 2024-11-22 00:25:44 +00:00
commit 1a386e78c3
parent b3b968bed9
31 changed files with 2515 additions and 4 deletions
--- a/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp
+++ b/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp
@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
+ * Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2024, Tim Flynn <trflynn89@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Temporal/AbstractOperations.h>
+#include <LibJS/Runtime/Temporal/Instant.h>
+#include <LibJS/Runtime/Temporal/PlainDateTime.h>
+
+namespace JS::Temporal {
+
+// 5.5.3 CombineISODateAndTimeRecord ( isoDate, time ), https://tc39.es/proposal-temporal/#sec-temporal-combineisodateandtimerecord
+ISODateTime combine_iso_date_and_time_record(ISODate iso_date, Time time)
+{
+    // 1. NOTE: time.[[Days]] is ignored.
+    // 2. Return ISO Date-Time Record { [[ISODate]]: isoDate, [[Time]]: time }.
+    return { .iso_date = iso_date, .time = time };
+}
+
+// nsMinInstant - nsPerDay
+static auto const DATETIME_NANOSECONDS_MIN = "-8640000086400000000000"_sbigint;
+
+// nsMaxInstant + nsPerDay
+static auto const DATETIME_NANOSECONDS_MAX = "8640000086400000000000"_sbigint;
+
+// 5.5.4 ISODateTimeWithinLimits ( isoDateTime ), https://tc39.es/proposal-temporal/#sec-temporal-isodatetimewithinlimits
+bool iso_date_time_within_limits(ISODateTime iso_date_time)
+{
+    // 1. If abs(ISODateToEpochDays(isoDateTime.[[ISODate]].[[Year]], isoDateTime.[[ISODate]].[[Month]] - 1, isoDateTime.[[ISODate]].[[Day]])) > 10**8 + 1, return false.
+    if (fabs(iso_date_to_epoch_days(iso_date_time.iso_date.year, iso_date_time.iso_date.month - 1, iso_date_time.iso_date.day)) > 100000001)
+        return false;
+
+    // 2. Let ns be ℝ(GetUTCEpochNanoseconds(isoDateTime)).
+    auto nanoseconds = get_utc_epoch_nanoseconds(iso_date_time);
+
+    // 3. If ns ≤ nsMinInstant - nsPerDay, then
+    if (nanoseconds <= DATETIME_NANOSECONDS_MIN) {
+        // a. Return false.
+        return false;
+    }
+
+    // 4. If ns ≥ nsMaxInstant + nsPerDay, then
+    if (nanoseconds >= DATETIME_NANOSECONDS_MAX) {
+        // a. Return false.
+        return false;
+    }
+
+    // 5. Return true.
+    return true;
+}
+
+}