Moment: Calendar Time callback function format returns corrupted month string

[dbshwang]

I was trying to use calendar time to format my dates by passing a callback function. However, in the else condition of my callback, the month of the formatted date is incorrect.

Jan returned as Jamn
Mar returned as 3amr
Feb returned as F0b

I might be doing this wrong but it seems weird that the month would come back this way without throwing any errors.

Code to reproduce

export const dateConversion = (date) => {
  // Assuming date comes in 'YYYY-MM-DD` format
  date = moment(date, 'YYYY-MM-DD');
  return date.calendar(null, {
    sameDay: '[Today]',
    nextDay: '[Tomorrow]',
    lastDay: '[Yesterday]',
    nextWeek: 'ddd',
    lastWeek: 'MMM D',
    sameElse: function(now) {
      if (this.isSame(now, 'year')) {
        return this.format('MMM D');
      } else {
        // Month is incorrectly parsed here 
        return this.format('MMM D, YYYY');
      }
    }
  });
}

Environment
Tue Mar 28 2017 16:52:21 GMT-0400 (EDT)
3/28/2017, 4:52:21 PM
240
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
2.17.1

[dbshwang]

nevermind - was returning the wrong value.

[avi-meslati-sp]

@dbshwang i'm having the same issue. can you please put your resolution

[dbshwang]

@avi-meslati-sp You should only be returning the string for formatting - not the actual formatted date. So in my case:

sameElse: function(now) {
  if (this.isSame(now, 'year')) {
      return this.format('MMM D');
  } else {
      return this.format('MMM D, YYYY');
  }
}

should actually be

sameElse: function(now) {
  if (this.isSame(now, 'year')) {
      return 'MMM D';
  } else {
      return 'MMM D, YYYY';
  }
}