Kata: codewars.com/r/8YQazg

Asked to write a accum fn that will take a string and will transform it repeating each character based on its position, the first letter should be capitalized and have - as separator. My solution was:

function accum(s) {
  return s.split('').map( 
    (char,index) => {
      if (index === 0){
        return char.toUpperCase()
      }

      return char.toUpperCase() + char.repeat(index).toLowerCase();
    }
  ).join('-');
}

That at the end of the day is not that bad but have one huge problem that I discovered checking one of the most accepted answer.

function accum(s) {
  return s.split('').map((c, i) => (c.toUpperCase() + c.toLowerCase().repeat(i))).join('-');
}

Beside the oneliner implementation did you spot my error?

Well I could entirely avoid the if condition because since we're repeating it based on index the first char has nothing to repeat() because index is 0 🤦‍♂️

Why am I doing this?

I does not fit in a single sentence so you can read more about here