AskJS Toy problem

/*
 * Names regex groups are really handy! Remember to end a regex with a ";"!
 */
const timeRegex = /(?<sHour>\d{1,2})(\:(?<sMinute>\d{1,2}))?\s(?<sAmPm>am|pm)\s\-\s(?<eHour>\d{1,2})(\:(?<eMinute>\d{1,2}))?\s(?<eAmPm>am|pm)/;
const daysRegex = /\b([a-zA-Z]{3,4}\-?)\b/g;
/*
 * Our tests:
 */
const tests = [
  "Mon-Sun 11:00 am - 10 pm",
  "Mon-Sun 11 am - 12 am",
  "Mon-Thu, Sat 11 am - 9 pm / Fri 5 pm - 9 pm",
  "Mon-Fri, Sat 11 am - 12 pm / Sun 11 am - 10 pm",
  "Mon-Thu, Sun 11:30 am - 10 pm / Fri-Sat 11:30 am - 11 pm",
  "Mon-Thu 11 am - 11 pm / Fri-Sat 11 am - 12:30 am / Sun 10 am - 11 pm"
]
/*
 * Our original object
 */
const daysObj = { "Mon": "", "Tues": "", "Wed": "", "Thu": "", "Fri": "", "Sat": "", "Sun": "" }
/*
 * Our array of days from the object above
 */
const days = Object.keys(daysObj)
/*
 * Our function to format a time
 */
const formatTime = (hour, minute, AmPm) => `${hour}:${minute} ${AmPm}`
/*
 * Our function to format a time duration
 */
const generateTime = (sHour, sMinute, sAmPm, eHour, eMinute, eAmPm) => {
  const sTime = formatTime(sHour, sMinute, sAmPm)
  const eTime = formatTime(eHour, eMinute, eAmPm)
  return `${sTime} - ${eTime}`
}
/*
 * Iterate over the tests
 */
for (const test of tests) {
 /*
  * Start with a fresh version of the days object by copying the one from above.
  */
  const returnObj = Object.assign({}, daysObj)
  /*
   * First we need to chunks of the string seperated by " / "
   * We'll then iterate over each chunk.
   */
  for (chunk of test.split(" / ")) {
    /*
     * We'll then get all the days from the chunk.
     */
    const daysResult = chunk.match(daysRegex)
    /*
     * We'll then destructure the groups from the regex match. Named regex groups are really helpful for this as we
     * we can then access the values by name from the groups object, and have default values for those that might be 
     * undefined.
     */
    const { sHour, sMinute = '00', sAmPm, eHour, eMinute = '00', eAmPm } = timeRegex.exec(chunk.trim()).groups
    /*
     * We'll then generate the time from the values we've extracted from the regex match.
     */
    const timeString = generateTime(sHour, sMinute, sAmPm, eHour, eMinute, eAmPm)
    /*
     * We'll then iterate over the days we've extracted from the chunk.
     */
    for (let i = 0; i < daysResult.length; i++) {
      /*
       * If the last character of the day is a hyphen, we know we need to iterate over the days array we created above.
       */
      if (daysResult[i].charAt(daysResult[i].length - 1) === "-") {
        /*
         * We'll then iterate over the days array we created above and populate it with the time string we've generated.
         */
        for (let l = days.findIndex(e => e === daysResult[i].slice(0, -1)); l < days.length; l++) {
          if (days[l] !== daysResult[i + 1]) {
            returnObj[days[l]] = timeString
          } else {
            /*
             * If the current day isn't the same as the next day in the array, we'll break.
             */
            break;
          }
        }
      } else {
        /*
         * If the last character of the day is not a hyphen, we can just set that day with the time string we've 
         * generated.
         */
        returnObj[daysResult[i]] = timeString
      }
    }
  }
  /*
   * Display the result along with the test
   */
  console.log(test, JSON.stringify(returnObj, null, 2))
}