feat: Temporal 三族新增 round 方法

Cargo.lock

@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1228,7 +1228,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1237,7 +1237,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1258,7 +1258,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1272,7 +1272,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1288,7 +1288,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1300,7 +1300,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_fold"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "num-bigint",
  "oxide_bytecode",
@@ -1312,7 +1312,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1321,7 +1321,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1335,7 +1335,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1347,7 +1347,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1356,11 +1356,11 @@ dependencies = [
 
 [[package]]
 name = "oxide_net"
-version = "0.19.11"
+version = "0.19.12"
 
 [[package]]
 name = "oxide_parser"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1375,7 +1375,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1391,7 +1391,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1404,7 +1404,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1424,7 +1424,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1437,7 +1437,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.19.11"
+version = "0.19.12"
 dependencies = [
  "bumpalo",
  "chrono",

Cargo.toml

@@ -25,7 +25,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.19.11"
+version = "0.19.12"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"

crates/oxide_builtins/src/temporal/common.rs

@@ -20,6 +20,7 @@ use oxide_runtime_api::{to_number, to_string, NativeResult, ProtoKind, VmHost};
 use oxide_types::object::JsObject;
 use oxide_types::value::JsValue;
 
+use super::instant::{instant_rounding_mode, InstantRoundingMode};
 use super::time_zone::{tz_canonical_name, zone_offset_seconds};
 use super::{
     parse_iso_date, parse_plain_date_time_string, parse_plain_time_string, valid_iso_date, valid_plain_date_time_range,
@@ -231,6 +232,68 @@ pub(crate) fn temporal_string_strict<H: VmHost>(vm: &mut H, value: JsValue) -> R
     Ok(to_string(primitive))
 }
 
+/// round 的 options 袋统一校验：roundTo 解析加 increment/mode/smallestUnit 读取与校验。
+///
+/// # 步骤
+/// 1. roundTo 字符串简写 → (1, halfExpand, Some(串))；对象 → 按固定读序
+///    roundingIncrement → roundingMode → smallestUnit 依次取值，全部读完再统一校验。
+/// 2. increment：undefined → 1.0；temporal_option_number；有限性；1..=1e9；截断取整。
+/// 3. mode：undefined → "halfExpand"；temporal_option_string；instant_rounding_mode
+///    查表（9 模式，None → RangeError）。
+/// 4. smallestUnit：undefined → None；temporal_option_string。
+///
+/// # 边界与前提
+/// - 非字符串非对象 → TypeError "roundTo must be a string or object"。
+/// - 单位表查表与真因子校验由调用方负责（单位表因类而异）。
+pub(crate) fn parse_round_options<H: VmHost>(
+    vm: &mut H, round_to: JsValue,
+) -> Result<(i128, InstantRoundingMode, Option<String>), JsValue> {
+    let (increment_raw, mode_raw, unit_raw) = if round_to.is_string() {
+        (JsValue::undefined(), JsValue::undefined(), round_to)
+    } else {
+        if !round_to.is_object() {
+            return Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
+        }
+        let options_ptr = round_to.as_js_object_ptr();
+        if options_ptr.is_null() {
+            return Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
+        }
+        let options = unsafe { &*options_ptr };
+        (
+            temporal_option_value(vm, options, round_to, "roundingIncrement")?,
+            temporal_option_value(vm, options, round_to, "roundingMode")?,
+            temporal_option_value(vm, options, round_to, "smallestUnit")?,
+        )
+    };
+    let increment_value = if increment_raw.is_undefined() {
+        1.0
+    } else {
+        temporal_option_number(vm, increment_raw)?
+    };
+    if !increment_value.is_finite() {
+        return Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+    }
+    let increment = increment_value.trunc();
+    if !(1.0..=1_000_000_000.0).contains(&increment) {
+        return Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+    }
+    let mode_value = if mode_raw.is_undefined() {
+        "halfExpand".to_string()
+    } else {
+        temporal_option_string(vm, mode_raw)?
+    };
+    let mode = match instant_rounding_mode(&mode_value) {
+        Some(mode) => mode,
+        None => return Err(crate::error::create_range_error(vm, "invalid rounding mode")),
+    };
+    let smallest_unit = if unit_raw.is_undefined() {
+        None
+    } else {
+        Some(temporal_option_string(vm, unit_raw)?)
+    };
+    Ok((increment as i128, mode, smallest_unit))
+}
+
 /// 校验 `with` 族方法的 partial 参数并排除日历/时区载体。
 ///
 /// 非对象、已初始化的 Temporal 日期时间类实例，或 calendar、timeZone 任一

crates/oxide_builtins/src/temporal/duration.rs

@@ -9,15 +9,15 @@ use super::common::native_try;
 use super::common::{
     canonical_time_zone, civil_from_days, days_from_civil, ensure_duration, get_calendar_id, get_double_prop,
     get_instant_epoch_ns, initialize_temporal_receiver, is_ctor_call, local_to_epoch_ns, month_code_well_formed,
-    native_engine_error, receiver_obj, resolve_date_time_parts, temporal_calendar_id, temporal_option_number,
-    temporal_option_string, temporal_option_value, temporal_string_strict, zoned_date_time_plain_parts, DateTimeParts,
+    native_engine_error, parse_round_options, receiver_obj, resolve_date_time_parts, temporal_calendar_id,
+    temporal_option_number, temporal_option_string, temporal_option_value, temporal_string_strict,
+    zoned_date_time_plain_parts, DateTimeParts,
 };
 use super::difference::{
     add_date_duration, add_days_iso, balance_instant_difference, compare_iso_date, date_duration_sign, date_until_iso,
     nudge_iso_difference, nudge_window, plain_date_time_unit_index, round_instant_difference, DifferenceSettings,
     InternalDuration, IsoDateTime, DAY_NS, MAX_ISO_DAY,
 };
-use super::instant::{instant_rounding_mode, InstantRoundingMode};
 use super::time_zone::zone_offset_seconds;
 use super::zoned_date_time::{
     add_zoned_datetime, difference_zoned_datetime_with_rounding_vm, difference_zoned_datetime_with_total_vm,
@@ -1240,14 +1240,9 @@ pub fn duration_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     }
 
     // roundTo 字符串 => { smallestUnit: 字符串 }；否则必须为对象。
-    let (largest_raw, relative_raw, increment_raw, mode_raw, smallest_raw) = if round_to.is_string() {
-        (
-            JsValue::undefined(),
-            JsValue::undefined(),
-            JsValue::undefined(),
-            JsValue::undefined(),
-            round_to,
-        )
+    // largestUnit/relativeTo 先于 increment 读取（读序钉死）；其余三字段走统一 helper。
+    let (largest_raw, relative_raw) = if round_to.is_string() {
+        (JsValue::undefined(), JsValue::undefined())
     } else {
         if !round_to.is_object() {
             return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be an object"));
@@ -1257,13 +1252,12 @@ pub fn duration_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
             return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be an object"));
         }
         let options = unsafe { &*options_ptr };
-        let largest_raw = native_try!(temporal_option_value(vm, options, round_to, "largestUnit"));
-        let relative_raw = native_try!(temporal_option_value(vm, options, round_to, "relativeTo"));
-        let increment_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingIncrement"));
-        let mode_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingMode"));
-        let smallest_raw = native_try!(temporal_option_value(vm, options, round_to, "smallestUnit"));
-        (largest_raw, relative_raw, increment_raw, mode_raw, smallest_raw)
+        (
+            native_try!(temporal_option_value(vm, options, round_to, "largestUnit")),
+            native_try!(temporal_option_value(vm, options, round_to, "relativeTo")),
+        )
     };
+    let (increment, mode, smallest_unit) = native_try!(parse_round_options(vm, round_to));
 
     // largestUnit：允许 "auto"；缺失/undefined 视为未提供。
     let largest_provided = !largest_raw.is_undefined();
@@ -1283,43 +1277,14 @@ pub fn duration_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
         }
     };
 
-    // roundingIncrement：ToIntegerOrInfinity 舍入后需在 [1, 10^9] 内。
-    let increment_value = if increment_raw.is_undefined() {
-        1.0
-    } else {
-        native_try!(temporal_option_number(vm, increment_raw))
-    };
-    let increment = increment_value.trunc();
-    if !increment.is_finite() || !(1.0..=1_000_000_000.0).contains(&increment) {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment as i128;
-
-    // roundingMode：缺失时 halfExpand。
-    let mode = if mode_raw.is_undefined() {
-        InstantRoundingMode::HalfExpand
-    } else {
-        let mode_string = native_try!(temporal_option_string(vm, mode_raw));
-        match instant_rounding_mode(&mode_string) {
-            Some(mode) => mode,
-            None => {
-                return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding mode"));
-            }
-        }
-    };
-
     // smallestUnit：缺失时 nanosecond。
-    let smallest_provided = !smallest_raw.is_undefined();
-    let smallest_index = if smallest_raw.is_undefined() {
-        9
-    } else {
-        let unit = native_try!(temporal_option_string(vm, smallest_raw));
-        match plain_date_time_unit_index(&unit) {
+    let smallest_provided = smallest_unit.is_some();
+    let smallest_index = match smallest_unit {
+        Some(unit) => match plain_date_time_unit_index(&unit) {
             Some(index) => index,
-            None => {
-                return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallestUnit"));
-            }
-        }
+            None => return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallestUnit")),
+        },
+        None => 9,
     };
 
     // 默认最大单位：现有最大单位与最小单位中较大（索引较小）的那个。

crates/oxide_builtins/src/temporal/instant.rs

@@ -12,8 +12,8 @@ use super::{
     balance_instant_difference, canonical_time_zone, civil_from_days, days_from_civil, days_in_month,
     duration_like_values, duration_time_nanoseconds, ensure_instant, format_iso_year, format_offset_seconds_text,
     get_instant_epoch_ns, initialize_temporal_receiver, is_ctor_call, make_duration, make_instant,
-    make_zoned_date_time, native_engine_error, parse_digits, parse_fractional_second_digits, receiver_obj,
-    round_instant_difference, temporal_option_number, temporal_option_string, temporal_option_value,
+    make_zoned_date_time, native_engine_error, parse_digits, parse_fractional_second_digits, parse_round_options,
+    receiver_obj, round_instant_difference, temporal_option_number, temporal_option_string, temporal_option_value,
     FractionalSecondDigitsInput, MAX_INSTANT_NS,
 };
 
@@ -551,55 +551,14 @@ pub fn instant_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     };
 
     let round_to = if args.len() < 2 { JsValue::undefined() } else { vm.reg(args[1]) };
-    let (increment_value, mode_value, unit_value) = if round_to.is_string() {
-        (1.0, "halfExpand".to_string(), Some(to_string(round_to)))
-    } else {
-        if !round_to.is_object() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options_ptr = round_to.as_js_object_ptr();
-        if options_ptr.is_null() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options = unsafe { &*options_ptr };
-        let increment_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingIncrement"));
-        let increment = if increment_raw.is_undefined() {
-            1.0
-        } else {
-            native_try!(temporal_option_number(vm, increment_raw))
-        };
-        let mode_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingMode"));
-        let mode = if mode_raw.is_undefined() {
-            "halfExpand".to_string()
-        } else {
-            native_try!(temporal_option_string(vm, mode_raw))
-        };
-        let unit_raw = native_try!(temporal_option_value(vm, options, round_to, "smallestUnit"));
-        let unit = if unit_raw.is_undefined() {
-            None
-        } else {
-            Some(native_try!(temporal_option_string(vm, unit_raw)))
-        };
-        (increment, mode, unit)
-    };
-
-    let Some(mode) = instant_rounding_mode(&mode_value) else {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding mode"));
-    };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
     let Some(unit_value) = unit_value else {
         return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
     };
     let Some((unit_ns, units_per_day)) = instant_round_unit(&unit_value) else {
         return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit"));
     };
-    if !increment_value.is_finite() {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment_value.trunc();
-    if !(1.0..=1_000_000_000.0).contains(&increment) {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment as i128;
+    // 整除校验用每更高一级单位数量（Instant 语义：增量须整除一天）。
     if units_per_day % increment != 0 {
         return NativeResult::Err(crate::error::create_range_error(vm, "rounding increment must divide a day"));
     }

crates/oxide_builtins/src/temporal/plain_date.rs

@@ -7,15 +7,18 @@ use oxide_types::value::JsValue;
 
 use super::common::native_try;
 use super::common::{
-    days_from_civil, days_in_month, ensure_plain_date, get_calendar_id, get_double_prop, initialize_temporal_receiver,
-    is_ctor_call, parse_plain_date_string, plain_date_time_object_parts, receiver_obj,
-    reject_partial_object_with_calendar_or_time_zone, resolve_date_time_parts, temporal_calendar_id,
-    temporal_calendar_id_strict, temporal_number_component, temporal_option_string, temporal_option_value,
-    temporal_overflow, zoned_date_time_plain_parts, DateTimeParts,
+    civil_from_days, days_from_civil, days_in_month, ensure_plain_date, get_calendar_id, get_double_prop,
+    initialize_temporal_receiver, is_ctor_call, parse_plain_date_string, parse_round_options,
+    plain_date_time_object_parts, receiver_obj, reject_partial_object_with_calendar_or_time_zone,
+    resolve_date_time_parts, temporal_calendar_id, temporal_calendar_id_strict, temporal_number_component,
+    temporal_option_string, temporal_option_value, temporal_overflow, zoned_date_time_plain_parts, DateTimeParts,
 };
 use super::difference::{difference_core, parse_difference_settings, IsoDateTime};
 use super::duration::duration_like_values;
-use super::{make_plain_date, make_plain_date_time, make_plain_month_day, make_plain_year_month, plain_time_like_ns};
+use super::{
+    make_plain_date, make_plain_date_time, make_plain_month_day, make_plain_year_month, plain_time_like_ns,
+    round_instant_ns,
+};
 
 /// 校验 ISO 日期分量（month 1-12、day 按月份与闰年，不依赖 chrono 年份范围）。
 pub(crate) fn valid_iso_date(year: i32, month: u32, day: u32) -> bool {
@@ -779,6 +782,95 @@ pub fn plain_date_subtract<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     date_apply_duration(vm, args, -1)
 }
 
+/// PlainDate round 的最小单位表：year/month/week/day。
+/// 返回 (单位日数, 最大增量)；日历单位无整除约束（最大增量 0）。
+pub(crate) fn plain_date_round_unit(value: &str) -> Option<(i128, i128)> {
+    match value {
+        "year" | "years" => Some((0, 0)),
+        "month" | "months" => Some((0, 0)),
+        "week" | "weeks" => Some((7, 0)),
+        "day" | "days" => Some((1, 0)),
+        _ => None,
+    }
+}
+
+/// `Temporal.PlainDate.prototype.round(roundTo)`：日历分量平衡到最小单位。
+///
+/// # 步骤
+/// 1. receiver 品牌校验；读槽 0-3 入本地（日历槽继承 receiver）。
+/// 2. roundTo 经 parse_round_options（undefined → TypeError；字符串简写；对象固定读序）。
+/// 3. 单位表查 smallestUnit（year/month/week/day；None → RangeError）；缺失 → RangeError。
+/// 4. day/week：日数按 increment × 单位日数舍入；month/year：总月数/年数按 increment 舍入。
+/// 5. month → 日钳制到目标月末；year → 月/日钳制到 1/1。
+/// 6. valid_iso_date 加 ISODateWithinLimits（±10^8 天，下界 -10^8-1）越界抛 RangeError。
+/// 7. make_plain_date 重建（日历槽继承 receiver）。
+///
+/// # 边界与前提
+/// - 日历单位（year/month/week）的 increment 无真因子约束。
+/// - 日数换算走 days_from_civil/civil_from_days（proleptic Gregorian，精确）。
+pub fn plain_date_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let ptr = native_try!(receiver_obj(vm, args));
+    let obj = unsafe { &*ptr };
+    native_try!(ensure_plain_date(vm, obj));
+    let year = get_double_prop(obj, 0) as i32;
+    let month = get_double_prop(obj, 1) as u32;
+    let day = get_double_prop(obj, 2) as u32;
+    let calendar = get_calendar_id(obj, 3);
+
+    let round_to = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
+    let Some(unit_value) = unit_value else {
+        return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
+    };
+    let (unit_days, max_increment) = match plain_date_round_unit(&unit_value) {
+        Some(entry) => entry,
+        None => return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit")),
+    };
+    if max_increment != 0 && (increment >= max_increment || max_increment % increment != 0) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+    }
+
+    let (year, month, day) = match unit_value.as_str() {
+        "day" | "days" | "week" | "weeks" => {
+            let days = days_from_civil(i128::from(year), i128::from(month), i128::from(day));
+            let Some(quantum) = unit_days.checked_mul(increment) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+            };
+            let Some(rounded_days) = round_instant_ns(days, quantum, mode) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "date is out of range"));
+            };
+            let (year, month, day) = civil_from_days(rounded_days);
+            (year as i32, month as u32, day as u32)
+        }
+        "month" | "months" => {
+            let total_months = i128::from(year) * 12 + i128::from(month) - 1;
+            let Some(rounded_months) = round_instant_ns(total_months, increment, mode) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "date is out of range"));
+            };
+            let year = rounded_months.div_euclid(12);
+            let month = rounded_months.rem_euclid(12) + 1;
+            let day = days_in_month(year, month).unwrap_or(31);
+            (year as i32, month as u32, day as u32)
+        }
+        "year" | "years" => {
+            let Some(rounded_year) = round_instant_ns(i128::from(year), increment, mode) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "date is out of range"));
+            };
+            (rounded_year as i32, 1, 1)
+        }
+        _ => unreachable!(),
+    };
+    if !valid_iso_date(year, month, day) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid ISO date"));
+    }
+    // 表示范围（ISODateWithinLimits）：-271821-04-19 … +275760-09-13。
+    let day_count = days_from_civil(i128::from(year), i128::from(month), i128::from(day));
+    if !(-100_000_001..=100_000_000).contains(&day_count) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "ISO date is out of range"));
+    }
+    make_plain_date(vm, year, month, day, &calendar)
+}
+
 fn add_signed_months(date: NaiveDate, months: i64) -> Option<NaiveDate> {
     let total = date.year() as i64 * 12 + date.month0() as i64 + months;
     let year = total.div_euclid(12);

crates/oxide_builtins/src/temporal/plain_date_time.rs

@@ -11,11 +11,12 @@ use super::{
     duration_like_values, ensure_plain_date_time, format_iso_year, get_calendar_id, get_double_prop,
     initialize_temporal_receiver, instant_rounding_mode, is_ctor_call, is_leap_year_iso, make_plain_date,
     make_plain_date_time, make_plain_time, parse_difference_settings, parse_fractional_second_digits,
-    parse_temporal_string_impl, plain_date_time_object_parts, plain_time_components, plain_time_like_ns, receiver_obj,
-    reject_partial_object_with_calendar_or_time_zone, resolve_date_time_parts, round_instant_ns, temporal_calendar_id,
-    temporal_calendar_id_strict, temporal_number_component, temporal_option_number, temporal_option_string,
-    temporal_option_value, temporal_overflow, valid_iso_date, valid_plain_date_time_range, valid_plain_time,
-    zoned_date_time_plain_parts, DateTimeParts, FractionalSecondDigitsInput, IsoDateTime,
+    parse_round_options, parse_temporal_string_impl, plain_date_time_object_parts, plain_time_components,
+    plain_time_like_ns, receiver_obj, reject_partial_object_with_calendar_or_time_zone, resolve_date_time_parts,
+    round_instant_ns, temporal_calendar_id, temporal_calendar_id_strict, temporal_number_component,
+    temporal_option_number, temporal_option_string, temporal_option_value, temporal_overflow, valid_iso_date,
+    valid_plain_date_time_range, valid_plain_time, zoned_date_time_plain_parts, DateTimeParts,
+    FractionalSecondDigitsInput, IsoDateTime,
 };
 // ───────────────────── PlainDateTime 基础方法 ─────────────────────
 
@@ -827,6 +828,98 @@ pub fn plain_date_time_subtract<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeRes
     plain_date_time_apply_duration(vm, args, -1)
 }
 
+/// PlainDateTime round 的最小单位表：day + 6 个时间单位（不含 year/month/week）。
+/// 返回 (单位纳秒, 最大增量)；day 的最大增量 = 1（仅 increment 1 合法）。
+pub(crate) fn plain_date_time_round_unit(value: &str) -> Option<(i128, i128)> {
+    match value {
+        "day" | "days" => Some((86_400_000_000_000, 1)),
+        "hour" | "hours" => Some((3_600_000_000_000, 24)),
+        "minute" | "minutes" => Some((60_000_000_000, 60)),
+        "second" | "seconds" => Some((1_000_000_000, 60)),
+        "millisecond" | "milliseconds" => Some((1_000_000, 1_000)),
+        "microsecond" | "microseconds" => Some((1_000, 1_000)),
+        "nanosecond" | "nanoseconds" => Some((1, 1_000)),
+        _ => None,
+    }
+}
+
+/// `Temporal.PlainDateTime.prototype.round(roundTo)`：日历分量平衡加纳秒算术。
+///
+/// # 步骤
+/// 1. receiver 品牌校验；读槽 0-4 入本地（日历槽继承 receiver）。
+/// 2. roundTo 经 parse_round_options（undefined → TypeError；字符串简写；对象固定读序）。
+/// 3. 单位表查 smallestUnit（day..nanosecond；None → RangeError）；缺失 → RangeError。
+/// 4. 真因子校验：day 仅 increment=1 合法（闭区间）；时间单位增量须严格小于最大增量且整除。
+/// 5. day：整日纳秒（日数 × 24h + 时间槽）按 increment × 24h 舍入 → 日期进位回填，时间槽清零。
+/// 6. 时间单位：时间槽按单位纳秒 × increment 舍入；≥24h 进位到日（日期 +1，时间槽减 24h）。
+/// 7. valid_iso_date 加 valid_plain_date_time_range（严格不等式）越界抛 RangeError。
+/// 8. make_plain_date_time 重建（日历槽继承 receiver）。
+///
+/// # 边界与前提
+/// - 舍入跨午夜（如 23:59:59.9 舍入到秒 → 次日 00:00）合法，同 rounding-cross-midnight 语义。
+/// - 进位至多一天（quantum < 24h 且时间槽 < 24h）。
+pub fn plain_date_time_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let ptr = native_try!(receiver_obj(vm, args));
+    let obj = unsafe { &*ptr };
+    native_try!(ensure_plain_date_time(vm, obj));
+    let year = get_double_prop(obj, 0) as i32;
+    let month = get_double_prop(obj, 1) as u32;
+    let day = get_double_prop(obj, 2) as u32;
+    let time_ns = get_double_prop(obj, 3) as i128;
+    let calendar = get_calendar_id(obj, 4);
+
+    let round_to = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
+    let Some(unit_value) = unit_value else {
+        return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
+    };
+    let Some((unit_ns, max_increment)) = plain_date_time_round_unit(&unit_value) else {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit"));
+    };
+    const DAY_NS: i128 = 86_400_000_000_000;
+    // 真因子校验：day 为闭区间（上界 1，仅 increment=1 合法）；时间单位增量须严格小于
+    // 上一级单位数量且整除。
+    let increment_valid = if unit_ns == DAY_NS {
+        increment == 1
+    } else {
+        increment < max_increment && max_increment % increment == 0
+    };
+    if !increment_valid {
+        return NativeResult::Err(crate::error::create_range_error(vm, "rounding increment must divide a day"));
+    }
+    let (year, month, day, time_ns) = if unit_ns == DAY_NS {
+        // day：整日纳秒（日数 × 24h + 时间槽）舍入，日期进位回填，时间槽清零。
+        let days = days_from_civil(i128::from(year), i128::from(month), i128::from(day));
+        let Some(total_ns) = days.checked_mul(DAY_NS).and_then(|value| value.checked_add(time_ns)) else {
+            return NativeResult::Err(crate::error::create_range_error(vm, "invalid date-time"));
+        };
+        let Some(rounded_ns) = round_instant_ns(total_ns, DAY_NS * increment, mode) else {
+            return NativeResult::Err(crate::error::create_range_error(vm, "invalid date-time"));
+        };
+        let (year, month, day) = civil_from_days(rounded_ns.div_euclid(DAY_NS));
+        (year as i32, month as u32, day as u32, rounded_ns.rem_euclid(DAY_NS))
+    } else {
+        // 时间单位：时间槽舍入，≥24h 进位到日（至多一天）。
+        let Some(quantum_ns) = unit_ns.checked_mul(increment) else {
+            return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+        };
+        let Some(rounded_ns) = round_instant_ns(time_ns, quantum_ns, mode) else {
+            return NativeResult::Err(crate::error::create_range_error(vm, "invalid time"));
+        };
+        if rounded_ns >= DAY_NS {
+            let days = days_from_civil(i128::from(year), i128::from(month), i128::from(day)) + 1;
+            let (year, month, day) = civil_from_days(days);
+            (year as i32, month as u32, day as u32, rounded_ns - DAY_NS)
+        } else {
+            (year, month, day, rounded_ns)
+        }
+    };
+    if !valid_iso_date(year, month, day) || !valid_plain_date_time_range(year, month, day, time_ns as f64) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid date-time"));
+    }
+    make_plain_date_time(vm, year, month, day, time_ns as f64, &calendar)
+}
+
 /// `Temporal.PlainDateTime.prototype.toJSON()`：输出默认 ISO 日期时间。
 pub fn plain_date_time_to_json<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     plain_date_time_iso_string(vm, args)

crates/oxide_builtins/src/temporal/plain_time.rs

@@ -9,7 +9,8 @@ use super::{
     difference_core, duration_component_integer, duration_like_values, ensure_plain_time, get_double_prop,
     initialize_temporal_receiver, instant_rounding_mode, instant_string_without_annotations, is_ctor_call,
     make_plain_time, parse_any_offset_seconds, parse_difference_settings, parse_fractional_second_digits,
-    parse_iso_date, receiver_obj, reject_partial_object_with_calendar_or_time_zone, round_instant_ns,
+    parse_iso_date, parse_round_options, receiver_obj, reject_partial_object_with_calendar_or_time_zone,
+    round_instant_ns,
     temporal_number_component, temporal_option_number, temporal_option_string, temporal_option_value,
     temporal_overflow, valid_offset_fraction, zoned_date_time_plain_parts, FractionalSecondDigitsInput, IsoDateTime,
 };
@@ -815,60 +816,19 @@ pub(crate) fn plain_time_round_unit(value: &str) -> Option<(i128, i128)> {
 /// - 舍入跨午夜（如 23:59:59.9 舍入到秒）→ 取模回 00:00，符合 rounding-cross-midnight 语义。
 pub fn plain_time_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     let round_to = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
-    let (increment_value, mode_value, unit_value) = if round_to.is_string() {
-        (1.0, "halfExpand".to_string(), Some(to_string(round_to)))
-    } else {
-        if !round_to.is_object() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options_ptr = round_to.as_js_object_ptr();
-        if options_ptr.is_null() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options = unsafe { &*options_ptr };
-        let increment_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingIncrement"));
-        let increment = if increment_raw.is_undefined() {
-            1.0
-        } else {
-            native_try!(temporal_option_number(vm, increment_raw))
-        };
-        let mode_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingMode"));
-        let mode = if mode_raw.is_undefined() {
-            "halfExpand".to_string()
-        } else {
-            native_try!(temporal_option_string(vm, mode_raw))
-        };
-        let unit_raw = native_try!(temporal_option_value(vm, options, round_to, "smallestUnit"));
-        let unit = if unit_raw.is_undefined() {
-            None
-        } else {
-            Some(native_try!(temporal_option_string(vm, unit_raw)))
-        };
-        (increment, mode, unit)
-    };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
 
     let ptr = native_try!(receiver_obj(vm, args));
     let obj = unsafe { &*ptr };
     native_try!(ensure_plain_time(vm, obj));
     let time_ns = get_double_prop(obj, 0) as i128;
 
-    let Some(mode) = instant_rounding_mode(&mode_value) else {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding mode"));
-    };
     let Some(unit_value) = unit_value else {
         return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
     };
     let Some((unit_ns, max_increment)) = plain_time_round_unit(&unit_value) else {
         return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit"));
     };
-    if !increment_value.is_finite() {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment_value.trunc();
-    if !(1.0..=1_000_000_000.0).contains(&increment) {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment as i128;
     // 真因子校验：增量须严格小于最大增量且能整除（MaximumTemporalDurationRoundingIncrement
     // 语义；instant_round 只查 % 的缺陷不在此沿用）。
     if increment >= max_increment || max_increment % increment != 0 {

crates/oxide_builtins/src/temporal/plain_year_month.rs

@@ -9,8 +9,9 @@ use super::{
     calendar_annotation, compare_iso_date, days_from_civil, days_in_month_iso, difference_core, duration_like_values,
     ensure_plain_year_month, format_iso_year, get_calendar_id, get_double_prop, initialize_temporal_receiver,
     is_ctor_call, is_leap_year_iso, iso_year_month_within_limits, make_duration, make_plain_date,
-    make_plain_year_month, month_day_bag_calendar_id, native_engine_error, parse_year_month_difference_settings,
-    read_iso2, receiver_obj, reject_partial_object_with_calendar_or_time_zone, temporal_constructor_calendar_id,
+    make_plain_year_month, month_day_bag_calendar_id, native_engine_error, parse_round_options,
+    parse_year_month_difference_settings, read_iso2, receiver_obj,
+    reject_partial_object_with_calendar_or_time_zone, round_instant_ns, temporal_constructor_calendar_id,
     temporal_number_component, temporal_option_string, temporal_option_value, temporal_overflow,
     temporal_to_show_calendar, validate_month_day_annotation_suffix, validate_month_day_time_suffix, IsoDateTime,
     ShowCalendar, MAX_ISO_DAY,
@@ -688,6 +689,73 @@ pub fn plain_year_month_subtract<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeRe
     plain_year_month_apply_duration(vm, args, -1)
 }
 
+/// PlainYearMonth round 的最小单位表：year/month。
+/// 返回 (单位月数, 最大增量)；日历单位无整除约束（最大增量 0）。
+pub(crate) fn plain_year_month_round_unit(value: &str) -> Option<(i128, i128)> {
+    match value {
+        "year" | "years" => Some((12, 0)),
+        "month" | "months" => Some((1, 0)),
+        _ => None,
+    }
+}
+
+/// `Temporal.PlainYearMonth.prototype.round(roundTo)`：日历分量平衡。
+///
+/// # 步骤
+/// 1. receiver 品牌校验；读槽 0-3 入本地（参考日槽 2 与日历槽继承 receiver）。
+/// 2. roundTo 经 parse_round_options（undefined → TypeError；字符串简写；对象固定读序）。
+/// 3. 单位表查 smallestUnit（year/month；None → RangeError）；缺失 → RangeError。
+/// 4. month：总月数（年 × 12 + 月 − 1）按 increment 舍入 → 年/月回填。
+/// 5. year：年数按 increment 舍入 → 月保持不变。
+/// 6. iso_year_month_within_limits 越界抛 RangeError。
+/// 7. make_plain_year_month 重建（参考日与日历槽继承 receiver）。
+///
+/// # 边界与前提
+/// - 日历单位（year/month）的 increment 无真因子约束。
+pub fn plain_year_month_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let ptr = native_try!(receiver_obj(vm, args));
+    let obj = unsafe { &*ptr };
+    native_try!(ensure_plain_year_month(vm, obj));
+    let year = get_double_prop(obj, 0) as i32;
+    let month = get_double_prop(obj, 1) as u32;
+    let ref_day = get_double_prop(obj, 2) as u32;
+    let calendar = get_calendar_id(obj, 3);
+
+    let round_to = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
+    let Some(unit_value) = unit_value else {
+        return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
+    };
+    let (_, max_increment) = match plain_year_month_round_unit(&unit_value) {
+        Some(entry) => entry,
+        None => return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit")),
+    };
+    if max_increment != 0 && (increment >= max_increment || max_increment % increment != 0) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
+    }
+
+    let (year, month) = match unit_value.as_str() {
+        "year" | "years" => {
+            let Some(rounded_year) = round_instant_ns(i128::from(year), increment, mode) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "year-month is out of range"));
+            };
+            (rounded_year as i32, month)
+        }
+        "month" | "months" => {
+            let total_months = i128::from(year) * 12 + i128::from(month) - 1;
+            let Some(rounded_months) = round_instant_ns(total_months, increment, mode) else {
+                return NativeResult::Err(crate::error::create_range_error(vm, "year-month is out of range"));
+            };
+            (rounded_months.div_euclid(12) as i32, rounded_months.rem_euclid(12) as u32 + 1)
+        }
+        _ => unreachable!(),
+    };
+    if !iso_year_month_within_limits(year, month) {
+        return NativeResult::Err(crate::error::create_range_error(vm, "invalid year-month"));
+    }
+    make_plain_year_month(vm, year, month, ref_day, &calendar)
+}
+
 /// `Temporal.PlainYearMonth.prototype.with(yearMonthLike[, options])`：覆盖 year/month/monthCode；
 /// undefined 不覆盖；calendar/timeZone 键拒绝；无识别字段 → TypeError。
 ///

crates/oxide_builtins/src/temporal/zoned_date_time.rs

@@ -11,7 +11,8 @@ use super::common::{
     canonical_time_zone, civil_from_days, days_from_civil, days_in_month, ensure_zoned_date_time, fixed_offset_seconds,
     format_iso_year, format_offset_seconds_text, get_calendar_id, get_double_prop, get_instant_epoch_ns,
     initialize_temporal_receiver, is_ctor_call, local_to_epoch_ns, make_instant, make_zoned_date_time, parse_digits,
-    parse_fractional_second_digits, parse_temporal_string_impl, plain_date_time_object_parts, receiver_obj,
+    parse_fractional_second_digits, parse_round_options, parse_temporal_string_impl, plain_date_time_object_parts,
+    receiver_obj,
     reject_partial_object_with_calendar_or_time_zone, temporal_calendar_id, temporal_calendar_id_strict,
     temporal_option_number, temporal_option_string, temporal_option_value, temporal_overflow, temporal_string_strict,
     zoned_date_time_plain_parts, FractionalSecondDigitsInput, MAX_INSTANT_NS,
@@ -1436,55 +1437,14 @@ pub fn zoned_date_time_round<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult
     // roundTo 解析：字符串简写直接取用，对象选项按 roundingIncrement、roundingMode、
     // smallestUnit 的固定读取顺序取值。
     let round_to = if args.len() < 2 { JsValue::undefined() } else { vm.reg(args[1]) };
-    let (increment_value, mode_value, unit_value) = if round_to.is_string() {
-        (1.0, "halfExpand".to_string(), Some(to_string(round_to)))
-    } else {
-        if !round_to.is_object() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options_ptr = round_to.as_js_object_ptr();
-        if options_ptr.is_null() {
-            return NativeResult::Err(crate::error::create_type_error(vm, "roundTo must be a string or object"));
-        }
-        let options = unsafe { &*options_ptr };
-        let increment_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingIncrement"));
-        let increment = if increment_raw.is_undefined() {
-            1.0
-        } else {
-            native_try!(temporal_option_number(vm, increment_raw))
-        };
-        let mode_raw = native_try!(temporal_option_value(vm, options, round_to, "roundingMode"));
-        let mode = if mode_raw.is_undefined() {
-            "halfExpand".to_string()
-        } else {
-            native_try!(temporal_option_string(vm, mode_raw))
-        };
-        let unit_raw = native_try!(temporal_option_value(vm, options, round_to, "smallestUnit"));
-        let unit = if unit_raw.is_undefined() {
-            None
-        } else {
-            Some(native_try!(temporal_option_string(vm, unit_raw)))
-        };
-        (increment, mode, unit)
-    };
+    let (increment, mode, unit_value) = native_try!(parse_round_options(vm, round_to));
 
-    let Some(mode) = instant_rounding_mode(&mode_value) else {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding mode"));
-    };
     let Some(unit_value) = unit_value else {
         return NativeResult::Err(crate::error::create_range_error(vm, "smallestUnit is required"));
     };
     let Some((unit_ns, units_per_day)) = zoned_date_time_round_unit(&unit_value) else {
         return NativeResult::Err(crate::error::create_range_error(vm, "invalid smallest unit"));
     };
-    if !increment_value.is_finite() {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment_value.trunc();
-    if !(1.0..=1_000_000_000.0).contains(&increment) {
-        return NativeResult::Err(crate::error::create_range_error(vm, "invalid rounding increment"));
-    }
-    let increment = increment as i128;
     // 真因子校验：时间单位增量须小于更高一级单位数量且整除（hour/24、minute/60、second/60 拒绝）；
     // day 特殊：更高一级数量=1，仅 increment==1 合法。
     let increment_valid = if unit_ns == DAY_NS {

crates/oxide_vm/src/bindings/bind_temporal.rs

@@ -588,6 +588,7 @@ pub fn bind_temporal(env: BindEnv<'_>, global: &mut JsObject) {
                 oxide_builtins::temporal::plain_date_to_plain_year_month::<crate::vm::Vm> as *const (),
                 0,
             ),
+            ("round", oxide_builtins::temporal::plain_date_round::<crate::vm::Vm> as *const (), 1),
         ],
     );
 
@@ -844,6 +845,11 @@ pub fn bind_temporal(env: BindEnv<'_>, global: &mut JsObject) {
                 oxide_builtins::temporal::plain_date_time_with_plain_time::<crate::vm::Vm> as *const (),
                 0,
             ),
+            (
+                "round",
+                oxide_builtins::temporal::plain_date_time_round::<crate::vm::Vm> as *const (),
+                1,
+            ),
         ],
     );
     bind_well_known_data_property(
@@ -1139,6 +1145,11 @@ pub fn bind_temporal(env: BindEnv<'_>, global: &mut JsObject) {
             ),
             ("until", oxide_builtins::temporal::plain_year_month_until::<crate::vm::Vm> as *const (), 1),
             ("since", oxide_builtins::temporal::plain_year_month_since::<crate::vm::Vm> as *const (), 1),
+            (
+                "round",
+                oxide_builtins::temporal::plain_year_month_round::<crate::vm::Vm> as *const (),
+                1,
+            ),
         ],
     );
     bind_well_known_data_property(

crates/oxide_vm/tests/builtins_temporal_tests.rs

@@ -4334,3 +4334,287 @@ fn plain_date_to_plain_month_day_and_year_month() {
         "M11|18|hebrew|1972-11-18[u-ca=hebrew]|1976|11|hebrew|1976-11-01[u-ca=hebrew]"
     );
 }
+
+// -- Temporal round 族（PD/PDT/PYM 新 round 与统一 options 袋）--
+
+#[test]
+fn plain_date_round_calendar_units() {
+    let mut vm = Vm::new();
+    // day：精确在日边界 → 原样。
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 18).round('day').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18");
+    // week：1976-11-18 恰在周边界（epoch 锚定）→ 原样；次日舍入回边界。
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 18).round('week').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18");
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 19).round('week').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18");
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 22).round('week').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-25");
+    // month：日钳制到目标月末（11 月 30 天）。
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 18).round('month').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-30");
+    // month 增量：1976-10 恰在 3 月边界 → 原样（日钳制到 10 月末）。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDate(1976, 10, 18).round({ smallestUnit: 'month', roundingIncrement: 3 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-10-31");
+    // 1976-11 越界（总月数余 1）→ 舍入回 1976-10。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDate(1976, 11, 18).round({ smallestUnit: 'month', roundingIncrement: 3 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-10-31");
+    // 闰年 2 月末：2000-02-29 舍入到月 → 2000-02-29。
+    let r = eval(&mut vm, "new Temporal.PlainDate(2000, 2, 29).round('month').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "2000-02-29");
+    // year：月/日钳制到 1/1。
+    let r = eval(&mut vm, "new Temporal.PlainDate(1976, 11, 18).round('year').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-01-01");
+    // year 增量：1977 按 4 舍入（1977 % 4 = 1 < 2）→ 1976-01-01。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDate(1977, 6, 15).round({ smallestUnit: 'year', roundingIncrement: 4 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-01-01");
+}
+
+#[test]
+fn plain_date_round_errors_and_calendar() {
+    let mut vm = Vm::new();
+    // 缺参 / undefined → TypeError（roundTo 非串非对象）。
+    let r = eval(&mut vm, "try { new Temporal.PlainDate(1976, 11, 18).round() } catch (e) { e.constructor.name }")
+        .unwrap();
+    assert_eq!(str_val(&vm, r), "TypeError");
+    // 对象缺 smallestUnit → RangeError。
+    let r = eval(&mut vm, "try { new Temporal.PlainDate(1976, 11, 18).round({}) } catch (e) { e.constructor.name }")
+        .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError");
+    // 非法最小单位（PD 限 year/month/week/day）→ RangeError。
+    let r = eval(
+        &mut vm,
+        "try { new Temporal.PlainDate(1976, 11, 18).round({ smallestUnit: 'hour' }) } catch (e) { e.constructor.name }",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError");
+    // NaN 增量 → RangeError。
+    let r = eval(
+        &mut vm,
+        "try { new Temporal.PlainDate(1976, 11, 18).round({ smallestUnit: 'week', roundingIncrement: NaN }) } catch (e) { e.constructor.name }",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError");
+    // 日历槽继承 receiver。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDate(1976, 11, 18, 'hebrew').round('month').calendarId",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "hebrew");
+}
+
+#[test]
+fn plain_date_time_round_time_units() {
+    let mut vm = Vm::new();
+    // second：0.6s 舍入到秒 → 进位（halfExpand 默认）。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30, 600, 0, 0).round({ smallestUnit: 'second' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18T14:23:31");
+    // nanosecond 增量 + floor：123456789ns → 123456700ns。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30, 123, 456, 789).round({ smallestUnit: 'nanosecond', roundingIncrement: 100, roundingMode: 'floor' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18T14:23:30.1234567");
+    // hour：23:59:59.999999999 舍入到小时 → 进位到次日 00:00。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 23, 59, 59, 999, 999, 999).round({ smallestUnit: 'hour' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-19T00:00:00");
+    // day：14:23:30 舍入到日（>12:00）→ 次日；floor → 当日。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30).round({ smallestUnit: 'day' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-19T00:00:00");
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 11, 23, 30).round({ smallestUnit: 'day', roundingMode: 'floor' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11-18T00:00:00");
+    // 跨年进位：2000-12-31T23:30 舍入到日 → 2001-01-01。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(2000, 12, 31, 23, 30).round({ smallestUnit: 'day' }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "2001-01-01T00:00:00");
+}
+
+#[test]
+fn plain_date_time_round_limits_and_errors() {
+    let mut vm = Vm::new();
+    // 表示范围边界（严格不等式）：min 舍入落边界下抛、max 舍入上越界抛。
+    let r = eval(
+        &mut vm,
+        "(() => { const kind = (fn) => { try { fn(); return 'no'; } catch (e) { return e.constructor.name; } };
+         const min = new Temporal.PlainDateTime(-271821, 4, 19, 0, 0, 0, 0, 0, 1);
+         const max = new Temporal.PlainDateTime(275760, 9, 13, 23, 59, 59, 999, 999, 999);
+         return [
+           kind(() => min.round({ smallestUnit: 'day', roundingMode: 'floor' })),
+           kind(() => max.round({ smallestUnit: 'hour', roundingMode: 'ceil' })),
+         ].join('|'); })()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError|RangeError");
+    // 缺参 → TypeError；对象缺 smallestUnit → RangeError。
+    let r = eval(
+        &mut vm,
+        "(() => { const kind = (fn) => { try { fn(); return 'no'; } catch (e) { return e.constructor.name; } };
+         const dt = new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30);
+         return [kind(() => dt.round()), kind(() => dt.round({}))].join('|'); })()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "TypeError|RangeError");
+    // 非法最小单位（PDT 限 day..nanosecond，year/month/week 不合法）→ RangeError。
+    let r = eval(
+        &mut vm,
+        "(() => { const kind = (fn) => { try { fn(); return 'no'; } catch (e) { return e.constructor.name; } };
+         const dt = new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30);
+         return [
+           kind(() => dt.round({ smallestUnit: 'year' })),
+           kind(() => dt.round({ smallestUnit: 'week' })),
+         ].join('|'); })()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError|RangeError");
+    // 真因子校验：hour 增量 24 拒绝；day 仅增量 1 合法。
+    let r = eval(
+        &mut vm,
+        "(() => { const kind = (fn) => { try { fn(); return 'no'; } catch (e) { return e.constructor.name; } };
+         const dt = new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30);
+         return [
+           kind(() => dt.round({ smallestUnit: 'hour', roundingIncrement: 24 })),
+           kind(() => dt.round({ smallestUnit: 'day', roundingIncrement: 2 })),
+         ].join('|'); })()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError|RangeError");
+    // 日历槽继承 receiver。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainDateTime(1976, 11, 18, 12, 0, 0, 0, 0, 0, 'hebrew').round('minute').calendarId",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "hebrew");
+}
+
+#[test]
+fn plain_year_month_round_units() {
+    let mut vm = Vm::new();
+    // month：1976-11 恰在 1 月边界 → 原样。
+    let r = eval(&mut vm, "new Temporal.PlainYearMonth(1976, 11).round('month').toString()").unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11");
+    // month 增量：1976-12 按 3 舍入（余 2 > 1.5）→ 1977-01。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainYearMonth(1976, 12).round({ smallestUnit: 'month', roundingIncrement: 3 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1977-01");
+    // year：1976 恰在 4 年边界 → 月不变（11）。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainYearMonth(1976, 11).round({ smallestUnit: 'year', roundingIncrement: 4 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11");
+    // year 增量：1977 按 4 舍入（余 1 < 2）→ 1976，月保持 11。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainYearMonth(1977, 11).round({ smallestUnit: 'year', roundingIncrement: 4 }).toString()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "1976-11");
+}
+
+#[test]
+fn plain_year_month_round_errors_and_calendar() {
+    let mut vm = Vm::new();
+    // 缺参 → TypeError；对象缺 smallestUnit → RangeError；非法单位（week）→ RangeError。
+    let r = eval(
+        &mut vm,
+        "(() => { const kind = (fn) => { try { fn(); return 'no'; } catch (e) { return e.constructor.name; } };
+         const ym = new Temporal.PlainYearMonth(1976, 11);
+         return [
+           kind(() => ym.round()),
+           kind(() => ym.round({})),
+           kind(() => ym.round({ smallestUnit: 'week' })),
+         ].join('|'); })()",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "TypeError|RangeError|RangeError");
+    // 范围边界：-271821-03 在表示范围外（下界 -271821-04）→ RangeError。
+    let r = eval(
+        &mut vm,
+        "try { new Temporal.PlainYearMonth(-271821, 3).round({ smallestUnit: 'month', roundingMode: 'floor' }) } catch (e) { e.constructor.name }",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "RangeError");
+    // 日历槽继承 receiver。
+    let r = eval(
+        &mut vm,
+        "new Temporal.PlainYearMonth(1976, 11, 'hebrew').round('year').calendarId",
+    )
+    .unwrap();
+    assert_eq!(str_val(&vm, r), "hebrew");
+}
+
+#[test]
+fn round_options_bag_shorthand_and_modes() {
+    let mut vm = Vm::new();
+    // 字符串简写与对象形态等价（PD/PDT/PYM 三族）。
+    let r = eval(
+        &mut vm,
+        "(() => {
+          const pd = new Temporal.PlainDate(1976, 11, 18);
+          const s = pd.round('month').toString();
+          const o = pd.round({ smallestUnit: 'month' }).toString();
+          const pds = new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30).round('day').toString();
+          const pdo = new Temporal.PlainDateTime(1976, 11, 18, 14, 23, 30).round({ smallestUnit: 'day' }).toString();
+          const yms = new Temporal.PlainYearMonth(1976, 12).round('year').toString();
+          const ymo = new Temporal.PlainYearMonth(1976, 12).round({ smallestUnit: 'year' }).toString();
+          return [s, o, pds, pdo, yms, ymo].join('|');
+        })()",
+    )
+    .unwrap();
+    assert_eq!(
+        str_val(&vm, r),
+        "1976-11-30|1976-11-30|1976-11-19T00:00:00|1976-11-19T00:00:00|1976-12|1976-12"
+    );
+    // 9 种舍入模式全过（PDT 时间单位路径）。
+    let r = eval(
+        &mut vm,
+        "(() => {
+          const dt = new Temporal.PlainDateTime(1976, 11, 18, 12, 30, 0);
+          const modes = ['ceil','expand','floor','halfCeil','halfEven','halfExpand','halfFloor','halfTrunc','trunc'];
+          return modes.map((m) => dt.round({ smallestUnit: 'hour', roundingMode: m }).toString()).join('|');
+        })()",
+    )
+    .unwrap();
+    assert_eq!(
+        str_val(&vm, r),
+        "1976-11-18T13:00:00|1976-11-18T13:00:00|1976-11-18T12:00:00|1976-11-18T13:00:00|1976-11-18T12:00:00|1976-11-18T13:00:00|1976-11-18T12:00:00|1976-11-18T12:00:00|1976-11-18T12:00:00"
+    );
+}