LibJS: Implement Temporal.PlainDateTime.prototype.round

Author: https://github.com/Lubrsi
Commit: https://github.com/SerenityOS/serenity/commit/d1a5254e416
Pull-request: https://github.com/SerenityOS/serenity/pull/10784
Reviewed-by: https://github.com/linusg ✅

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

@@ -284,6 +284,39 @@ ThrowCompletionOr<u64> to_temporal_rounding_increment(GlobalObject& global_objec
     return floored_increment;
 }
 
+// 13.15 ToTemporalDateTimeRoundingIncrement ( normalizedOptions, smallestUnit ), https://tc39.es/proposal-temporal/#sec-temporal-totemporaldatetimeroundingincrement
+ThrowCompletionOr<u64> to_temporal_date_time_rounding_increment(GlobalObject& global_object, Object const& normalized_options, StringView smallest_unit)
+{
+    double maximum;
+
+    // 1. If smallestUnit is "day", then
+    if (smallest_unit == "day"sv) {
+        // a. Let maximum be 1.
+        maximum = 1;
+    }
+    // 2. Else if smallestUnit is "hour", then
+    else if (smallest_unit == "hour"sv) {
+        // a. Let maximum be 24.
+        maximum = 24;
+    }
+    // 3. Else if smallestUnit is "minute" or "second", then
+    else if (smallest_unit.is_one_of("minute"sv, "second"sv)) {
+        // a. Let maximum be 60.
+        maximum = 60;
+    }
+    // 4. Else,
+    else {
+        // a. Assert: smallestUnit is "millisecond", "microsecond", or "nanosecond".
+        VERIFY(smallest_unit.is_one_of("millisecond"sv, "microsecond"sv, "nanosecond"sv));
+
+        // b. Let maximum be 1000.
+        maximum = 1000;
+    }
+
+    // 5. Return ? ToTemporalRoundingIncrement(normalizedOptions, maximum, false).
+    return to_temporal_rounding_increment(global_object, normalized_options, maximum, false);
+}
+
 // 13.16 ToSecondsStringPrecision ( normalizedOptions ), https://tc39.es/proposal-temporal/#sec-temporal-tosecondsstringprecision
 ThrowCompletionOr<SecondsStringPrecision> to_seconds_string_precision(GlobalObject& global_object, Object const& normalized_options)
 {

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

@@ -94,6 +94,7 @@ ThrowCompletionOr<String> to_temporal_disambiguation(GlobalObject&, Object const
 ThrowCompletionOr<String> to_temporal_rounding_mode(GlobalObject&, Object const& normalized_options, String const& fallback);
 ThrowCompletionOr<String> to_show_calendar_option(GlobalObject&, Object const& normalized_options);
 ThrowCompletionOr<u64> to_temporal_rounding_increment(GlobalObject&, Object const& normalized_options, Optional<double> dividend, bool inclusive);
+ThrowCompletionOr<u64> to_temporal_date_time_rounding_increment(GlobalObject&, Object const& normalized_options, StringView smallest_unit);
 ThrowCompletionOr<SecondsStringPrecision> to_seconds_string_precision(GlobalObject&, Object const& normalized_options);
 ThrowCompletionOr<String> to_largest_temporal_unit(GlobalObject&, Object const& normalized_options, Vector<StringView> const& disallowed_units, String const& fallback, Optional<String> auto_value);
 ThrowCompletionOr<Optional<String>> to_smallest_temporal_unit(GlobalObject&, Object const& normalized_options, Vector<StringView> const& disallowed_units, Optional<String> fallback);

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

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -62,6 +63,7 @@ void PlainDateTimePrototype::initialize(GlobalObject& global_object)
     define_native_function(vm.names.withCalendar, with_calendar, 1, attr);
     define_native_function(vm.names.add, add, 1, attr);
     define_native_function(vm.names.subtract, subtract, 1, attr);
+    define_native_function(vm.names.round, round, 1, attr);
     define_native_function(vm.names.equals, equals, 1, attr);
     define_native_function(vm.names.toString, to_string, 0, attr);
     define_native_function(vm.names.toLocaleString, to_locale_string, 0, attr);
@@ -451,6 +453,45 @@ JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::subtract)
     return TRY(create_temporal_date_time(global_object, result.year, result.month, result.day, result.hour, result.minute, result.second, result.millisecond, result.microsecond, result.nanosecond, date_time->calendar()));
 }
 
+// 5.3.30 Temporal.PlainDateTime.prototype.round ( options ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.round
+JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::round)
+{
+    // 1. Let dateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(dateTime, [[InitializedTemporalDateTime]]).
+    auto* date_time = TRY(typed_this_object(global_object));
+
+    // 3. If options is undefined, then
+    if (vm.argument(0).is_undefined()) {
+        // a. Throw a TypeError exception.
+        return vm.throw_completion<TypeError>(global_object, ErrorType::TemporalMissingOptionsObject);
+    }
+
+    // 4. Set options to ? GetOptionsObject(options).
+    auto* options = TRY(get_options_object(global_object, vm.argument(0)));
+
+    // 5. Let smallestUnit be ? ToSmallestTemporalUnit(options, « "year", "month", "week" », undefined).
+    auto smallest_unit_value = TRY(to_smallest_temporal_unit(global_object, *options, { "year"sv, "month"sv, "week"sv }, {}));
+
+    // 6. If smallestUnit is undefined, throw a RangeError exception.
+    if (!smallest_unit_value.has_value())
+        return vm.throw_completion<RangeError>(global_object, ErrorType::OptionIsNotValidValue, vm.names.undefined.as_string(), "smallestUnit");
+
+    // NOTE: At this point smallest_unit_value can only be a string
+    auto& smallest_unit = *smallest_unit_value;
+
+    // 7. Let roundingMode be ? ToTemporalRoundingMode(options, "halfExpand").
+    auto rounding_mode = TRY(to_temporal_rounding_mode(global_object, *options, "halfExpand"));
+
+    // 8. Let roundingIncrement be ? ToTemporalDateTimeRoundingIncrement(options, smallestUnit).
+    auto rounding_increment = TRY(to_temporal_date_time_rounding_increment(global_object, *options, smallest_unit));
+
+    // 9. Let result be ! RoundISODateTime(dateTime.[[ISOYear]], dateTime.[[ISOMonth]], dateTime.[[ISODay]], dateTime.[[ISOHour]], dateTime.[[ISOMinute]], dateTime.[[ISOSecond]], dateTime.[[ISOMillisecond]], dateTime.[[ISOMicrosecond]], dateTime.[[ISONanosecond]], roundingIncrement, smallestUnit, roundingMode).
+    auto result = round_iso_date_time(date_time->iso_year(), date_time->iso_month(), date_time->iso_day(), date_time->iso_hour(), date_time->iso_minute(), date_time->iso_second(), date_time->iso_millisecond(), date_time->iso_microsecond(), date_time->iso_nanosecond(), rounding_increment, smallest_unit, rounding_mode);
+
+    // 10. Return ? CreateTemporalDateTime(result.[[Year]], result.[[Month]], result.[[Day]], result.[[Hour]], result.[[Minute]], result.[[Second]], result.[[Millisecond]], result.[[Microsecond]], result.[[Nanosecond]], dateTime.[[Calendar]]).
+    return TRY(create_temporal_date_time(global_object, result.year, result.month, result.day, result.hour, result.minute, result.second, result.millisecond, result.microsecond, result.nanosecond, date_time->calendar()));
+}
+
 // 5.3.31 Temporal.PlainDateTime.prototype.equals ( other ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.equals
 JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::equals)
 {

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

@@ -46,6 +46,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(with_calendar);
     JS_DECLARE_NATIVE_FUNCTION(add);
     JS_DECLARE_NATIVE_FUNCTION(subtract);
+    JS_DECLARE_NATIVE_FUNCTION(round);
     JS_DECLARE_NATIVE_FUNCTION(equals);
     JS_DECLARE_NATIVE_FUNCTION(to_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_string);

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.round.js

@@ -0,0 +1,139 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainDateTime.prototype.round).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+
+        const firstRoundedPlainDateTime = plainDateTime.round({ smallestUnit: "minute" });
+        expect(firstRoundedPlainDateTime.year).toBe(2021);
+        expect(firstRoundedPlainDateTime.month).toBe(11);
+        expect(firstRoundedPlainDateTime.monthCode).toBe("M11");
+        expect(firstRoundedPlainDateTime.day).toBe(3);
+        expect(firstRoundedPlainDateTime.hour).toBe(18);
+        expect(firstRoundedPlainDateTime.minute).toBe(8);
+        expect(firstRoundedPlainDateTime.second).toBe(0);
+        expect(firstRoundedPlainDateTime.millisecond).toBe(0);
+        expect(firstRoundedPlainDateTime.microsecond).toBe(0);
+        expect(firstRoundedPlainDateTime.nanosecond).toBe(0);
+
+        const secondRoundedPlainDateTime = plainDateTime.round({
+            smallestUnit: "minute",
+            roundingMode: "ceil",
+        });
+        expect(secondRoundedPlainDateTime.year).toBe(2021);
+        expect(secondRoundedPlainDateTime.month).toBe(11);
+        expect(secondRoundedPlainDateTime.monthCode).toBe("M11");
+        expect(secondRoundedPlainDateTime.day).toBe(3);
+        expect(secondRoundedPlainDateTime.hour).toBe(18);
+        expect(secondRoundedPlainDateTime.minute).toBe(9);
+        expect(secondRoundedPlainDateTime.second).toBe(0);
+        expect(secondRoundedPlainDateTime.millisecond).toBe(0);
+        expect(secondRoundedPlainDateTime.microsecond).toBe(0);
+        expect(secondRoundedPlainDateTime.nanosecond).toBe(0);
+
+        const thirdRoundedPlainDateTime = plainDateTime.round({
+            smallestUnit: "minute",
+            roundingMode: "ceil",
+            roundingIncrement: 30,
+        });
+        expect(thirdRoundedPlainDateTime.year).toBe(2021);
+        expect(thirdRoundedPlainDateTime.month).toBe(11);
+        expect(thirdRoundedPlainDateTime.monthCode).toBe("M11");
+        expect(thirdRoundedPlainDateTime.day).toBe(3);
+        expect(thirdRoundedPlainDateTime.hour).toBe(18);
+        expect(thirdRoundedPlainDateTime.minute).toBe(30);
+        expect(thirdRoundedPlainDateTime.second).toBe(0);
+        expect(thirdRoundedPlainDateTime.millisecond).toBe(0);
+        expect(thirdRoundedPlainDateTime.microsecond).toBe(0);
+        expect(thirdRoundedPlainDateTime.nanosecond).toBe(0);
+
+        const fourthRoundedPlainDateTime = plainDateTime.round({
+            smallestUnit: "minute",
+            roundingMode: "floor",
+            roundingIncrement: 30,
+        });
+        expect(fourthRoundedPlainDateTime.year).toBe(2021);
+        expect(fourthRoundedPlainDateTime.month).toBe(11);
+        expect(fourthRoundedPlainDateTime.monthCode).toBe("M11");
+        expect(fourthRoundedPlainDateTime.day).toBe(3);
+        expect(fourthRoundedPlainDateTime.hour).toBe(18);
+        expect(fourthRoundedPlainDateTime.minute).toBe(0);
+        expect(fourthRoundedPlainDateTime.second).toBe(0);
+        expect(fourthRoundedPlainDateTime.millisecond).toBe(0);
+        expect(fourthRoundedPlainDateTime.microsecond).toBe(0);
+        expect(fourthRoundedPlainDateTime.nanosecond).toBe(0);
+
+        const fifthRoundedPlainDateTime = plainDateTime.round({
+            smallestUnit: "hour",
+            roundingMode: "halfExpand",
+            roundingIncrement: 4,
+        });
+        expect(fifthRoundedPlainDateTime.year).toBe(2021);
+        expect(fifthRoundedPlainDateTime.month).toBe(11);
+        expect(fifthRoundedPlainDateTime.monthCode).toBe("M11");
+        expect(fifthRoundedPlainDateTime.day).toBe(3);
+        expect(fifthRoundedPlainDateTime.hour).toBe(20);
+        expect(fifthRoundedPlainDateTime.minute).toBe(0);
+        expect(fifthRoundedPlainDateTime.second).toBe(0);
+        expect(fifthRoundedPlainDateTime.millisecond).toBe(0);
+        expect(fifthRoundedPlainDateTime.microsecond).toBe(0);
+        expect(fifthRoundedPlainDateTime.nanosecond).toBe(0);
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.PlainDateTime object", () => {
+        expect(() => {
+            Temporal.PlainDateTime.prototype.round.call("foo", {});
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.PlainDateTime");
+    });
+
+    test("missing options object", () => {
+        expect(() => {
+            const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+            plainDateTime.round();
+        }).toThrowWithMessage(TypeError, "Required options object is missing or undefined");
+    });
+
+    test("invalid rounding mode", () => {
+        expect(() => {
+            const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+            plainDateTime.round({ smallestUnit: "second", roundingMode: "serenityOS" });
+        }).toThrowWithMessage(
+            RangeError,
+            "serenityOS is not a valid value for option roundingMode"
+        );
+    });
+
+    test("invalid smallest unit", () => {
+        expect(() => {
+            const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+            plainDateTime.round({ smallestUnit: "serenityOS" });
+        }).toThrowWithMessage(
+            RangeError,
+            "serenityOS is not a valid value for option smallestUnit"
+        );
+    });
+
+    test("increment may not be NaN", () => {
+        expect(() => {
+            const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+            plainDateTime.round({ smallestUnit: "second", roundingIncrement: NaN });
+        }).toThrowWithMessage(RangeError, "NaN is not a valid value for option roundingIncrement");
+    });
+
+    test("increment may not be smaller than 1 or larger than maximum", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+        expect(() => {
+            plainDateTime.round({ smallestUnit: "second", roundingIncrement: -1 });
+        }).toThrowWithMessage(RangeError, "-1 is not a valid value for option roundingIncrement");
+        expect(() => {
+            plainDateTime.round({ smallestUnit: "second", roundingIncrement: 0 });
+        }).toThrowWithMessage(RangeError, "0 is not a valid value for option roundingIncrement");
+        expect(() => {
+            plainDateTime.round({ smallestUnit: "second", roundingIncrement: Infinity });
+        }).toThrowWithMessage(RangeError, "inf is not a valid value for option roundingIncrement");
+    });
+});