问Luxon.js获取给定日期范围内每个月的天数

EN

const firstDateToPass = { year: 2020, month: 1, day: 26 };
const secondDateToPass = { year: 2020, month: 1, day: 29 };

const getCountOfDaysGroupedByMonth = (startDate, endDate) => {
  const firstMonthDateTime = DateTime.fromObject(startDate);
  const secondMonthDateTime = DateTime.fromObject(endDate);
  if (firstMonthDateTime.month === secondMonthDateTime.month) {
    // In same month
    // Return difference in days
    return {
      [firstMonthDateTime.monthLong]: secondMonthDateTime.day - firstMonthDateTime.day
    }
  }
}

console.log(getCountOfDaysGroupedByMonth(firstDateToPass, secondDateToPass)) // { January: 3 }