JavaScript Temporal 可以直接用了嗎？新舊專案的導入判斷

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import assert from 'node:assert/strict';
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// 1. 只有日期的欄位：Date 把 '2026-03-08' 當成 UTC 午夜
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const legacy = new Date('2026-03-08');
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assert.equal(legacy.getDate(), 7); // 在洛杉磯時區讀到前一天
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const due = Temporal.PlainDate.from('2026-03-08');
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assert.equal(due.day, 8);
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// 2. 1 月 31 日加一個月
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const d = new Date(2026, 0, 31);
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d.setMonth(d.getMonth() + 1);
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assert.equal(d.toDateString(), 'Tue Mar 03 2026'); // 溢出到 3 月
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const jan31 = Temporal.PlainDate.from('2026-01-31');
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assert.equal(jan31.add({ months: 1 }).toString(), '2026-02-28');
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assert.throws(() => jan31.add({ months: 1 }, { overflow: 'reject' }), RangeError);
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// 3. 跨夏令時間的「明天同一時間」
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const meeting = Temporal.ZonedDateTime.from('2026-03-07T09:00[America/New_York]');
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const nextDay = meeting.add({ days: 1 });
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assert.equal(nextDay.toString(), '2026-03-08T09:00:00-04:00[America/New_York]');
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assert.equal(meeting.until(nextDay).total({ unit: 'hours' }), 23);
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assert.equal(
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  meeting.add({ hours: 24 }).toString(),
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  '2026-03-08T10:00:00-04:00[America/New_York]',
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);
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// 4. 不存在的日期與不可變物件
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assert.throws(() => Temporal.PlainDate.from('2026-02-30'), RangeError);
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const start = Temporal.PlainDate.from('2026-11-14');
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const end = start.add({ days: 7 });
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assert.equal(start.toString(), '2026-11-14');
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assert.equal(end.toString(), '2026-11-21');
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// 顯示成台北時間
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const instant = Temporal.Instant.from('2026-11-14T04:30:00Z');
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assert.equal(
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  instant.toZonedDateTimeISO('Asia/Taipei').toPlainDateTime().toString(),
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  '2026-11-14T12:30:00',
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);
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console.log('Temporal 檢查通過', process.version);