feat(ecmascript): PlainTime.prototype.round

Author: 0Zeno

nova_vm/src/ecmascript/builtins/temporal/plain_time/plain_time_prototype.rs

@@ -2,16 +2,20 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+use temporal_rs::options::{RoundingMode, RoundingOptions, Unit};
+
 use crate::{
     ecmascript::{
-        Agent, ArgumentsList, BUILTIN_STRING_MEMORY, Behaviour, Builtin, BuiltinGetter, JsResult,
-        PropertyKey, Realm, String, Value,
+        Agent, ArgumentsList, BUILTIN_STRING_MEMORY, Behaviour, Builtin, BuiltinGetter,
+        ExceptionType, JsResult, PropertyKey, Realm, String, StringOptionType, Value,
         builders::OrdinaryObjectBuilder,
         builtins::temporal::plain_time::{
             add_duration_to_time, require_internal_slot_temporal_plain_time,
         },
+        create_temporal_plain_time, get_options_object, get_rounding_increment_option,
+        get_rounding_mode_option, get_temporal_unit_valued_option, temporal_err_to_js_err,
     },
-    engine::{Bindable, GcScope, NoGcScope},
+    engine::{Bindable, GcScope, NoGcScope, Scopable},
     heap::WellKnownSymbols,
 };
 
@@ -90,6 +94,12 @@ impl Builtin for TemporalPlainTimePrototypeSubtract {
     const BEHAVIOUR: Behaviour = Behaviour::Regular(TemporalPlainTimePrototype::subtract);
 }
 
+struct TemporalPlainTimePrototypeRound;
+impl Builtin for TemporalPlainTimePrototypeRound {
+    const NAME: String<'static> = BUILTIN_STRING_MEMORY.round;
+    const LENGTH: u8 = 1;
+    const BEHAVIOUR: Behaviour = Behaviour::Regular(TemporalPlainTimePrototype::round);
+}
 impl TemporalPlainTimePrototype {
     /// ### [4.3.4 get Temporal.PlainTime.prototype.minute](https://tc39.es/proposal-temporal/#sec-get-temporal.plaintime.prototype.minute)
     pub(crate) fn get_minute<'gc>(
@@ -228,6 +238,96 @@ impl TemporalPlainTimePrototype {
             .map(Value::from)
     }
 
+    /// ### [5.3.14 Temporal.PlainTime.prototype.round ( roundTo )](https://tc39.es/proposal-temporal/#sec-temporal.plaintime.prototype.round)
+    fn round<'gc>(
+        agent: &mut Agent,
+        this_value: Value,
+        args: ArgumentsList,
+        mut gc: GcScope<'gc, '_>,
+    ) -> JsResult<'gc, Value<'gc>> {
+        let this_value = this_value.bind(gc.nogc());
+        let round_to = args.get(0).bind(gc.nogc());
+        // 1. Let plainTime be the this value.
+        // 2. Perform ? RequireInternalSlot(plainTime, [[InitializedTemporalTime]]).
+        let plain_time = require_internal_slot_temporal_plain_time(agent, this_value, gc.nogc())
+            .unbind()?;
+        let inner_time = plain_time.inner_plain_time(agent);
+        // 3. If roundTo is undefined, throw a TypeError exception.
+        if round_to.is_undefined() {
+            return Err(agent.throw_exception_with_static_message(
+                ExceptionType::TypeError,
+                "rountTo cannot be undefined",
+                gc.into_nogc(),
+            ));
+        }
+
+        // 4. If roundTo is a String, then
+        let options = if let Ok(round_to) = String::try_from(round_to) {
+            // a. Let paramString be roundTo.
+            // b. Set roundTo to OrdinaryObjectCreate(null).
+            // c. Perform ! CreateDataPropertyOrThrow(roundTo, "smallestUnit", paramString).
+            let mut options = RoundingOptions::default();
+            options.smallest_unit =
+                Some(Unit::from_string(agent, round_to.unbind(), gc.nogc()).unbind()?);
+            options
+        } else {
+            // 5. Else,
+            // a. Set roundTo to ? GetOptionsObject(roundTo).
+            let round_to = get_options_object(agent, round_to, gc.nogc())
+                .unbind()?
+                .map(|r| r.scope(agent, gc.nogc()));
+            // 6. NOTE: The following steps read options and perform independent validation in alphabetical
+            // order (GetRoundingIncrementOption reads "roundingIncrement" and GetRoundingModeOption reads "roundingMode").
+            let mut options = RoundingOptions::default();
+
+            let (rounding_increment, rounding_mode, smallest_unit) =
+                if let Some(round_to) = round_to {
+                    // 7. Let roundingIncrement be ? GetRoundingIncrementOption(roundTo).
+                    let rounding_increment =
+                        get_rounding_increment_option(agent, round_to.get(agent), gc.reborrow())
+                            .unbind()?;
+                    // 8. Let roundingMode be ? GetRoundingModeOption(roundTo, half-expand).
+                    let rounding_mode = get_rounding_mode_option(
+                        agent,
+                        round_to.get(agent),
+                        RoundingMode::default(),
+                        gc.reborrow(),
+                    )
+                    .unbind()?;
+                    // 9. Let smallestUnit be ? GetTemporalUnitValuedOption(roundTo, "smallestUnit", required).
+                    let smallest_unit = get_temporal_unit_valued_option(
+                        agent,
+                        round_to.get(agent),
+                        BUILTIN_STRING_MEMORY.smallestUnit.into(),
+                        gc.reborrow(),
+                    )
+                    .unbind()?;
+                    (rounding_increment, rounding_mode, smallest_unit)
+                } else {
+                    Default::default()
+                };
+
+            options.increment = Some(rounding_increment);
+            options.rounding_mode = Some(rounding_mode);
+            options.smallest_unit = smallest_unit;
+            options
+        };
+
+        // 10. Perform ? ValidateTemporalUnitValue(smallestUnit, time).
+        // 11. Let maximum be MaximumTemporalDurationRoundingIncrement(smallestUnit).
+        // 12. Assert: maximum is not unset.
+        // 13. Perform ? ValidateTemporalRoundingIncrement(roundingIncrement, maximum, false).
+        // 14. Let result be RoundTime(plainTime.[[Time]], roundingIncrement, smallestUnit, roundingMode).
+        let result = inner_time
+            .round(options)
+            .map_err(|e| temporal_err_to_js_err(agent, e, gc.nogc()))
+            .unbind()?;
+        // 15. Return ! CreateTemporalTime(result).
+        Ok(create_temporal_plain_time(agent, result, None, gc)
+            .unwrap()
+            .into())
+    }
+
     pub(crate) fn create_intrinsic(agent: &mut Agent, realm: Realm<'static>, _: NoGcScope) {
         let intrinsics = agent.get_realm_record_by_id(realm).intrinsics();
         let this = intrinsics.temporal_plain_time_prototype();
@@ -246,6 +346,7 @@ impl TemporalPlainTimePrototype {
             .with_builtin_function_getter_property::<TemporalPlainTimePrototypeGetMillisecond>()
             .with_builtin_function_property::<TemporalPlainTimePrototypeAdd>()
             .with_builtin_function_property::<TemporalPlainTimePrototypeSubtract>()
+            .with_builtin_function_property::<TemporalPlainTimePrototypeRound>()
             .with_property(|builder| {
                 builder
                     .with_key(WellKnownSymbols::ToStringTag.into())