String.prototype.hashify = function () {
  const arr = this.toString().split('');
  let obj = {};
  let previousKey, currentKey;

  for (let i=0; i<arr.length; i++) {

    currentKey = arr[i];

    if (!obj[currentKey]) {
      if (i < arr.length -1) {
        obj[currentKey] = [arr[i+1]];
      }
    } else {
      console.log('ELSE', i);
      obj[previousKey].push(arr[i+1]);
    }
    if (i === arr.length - 1) {
      console.log('LAST', currentKey);
      obj[currentKey] = [arr[0]];
    }
    previousKey = currentKey;
    console.log(obj);
  }

  // console.log(obj);
  return obj;


};

console.log('raracrceaec'.hashify());


// Correct results is {"r":["a","r"],"a":["c","r"],"c":["e","a"],"e":"c"} - Expected: 'true', instead got: 'false'


/**
'123456'.hashify() == {"1":"2","2":"3","3":"4","4":"5","5":"6","6":"1"} // The last char will be key for 1st
char
'11223'.hashify() == {"1":["1","2"],"2":["2","3"],"3":"1"} // when duplicates exist, group them in an array
// i.e. 1 is key for next char 1, that 1 is key for next char 2, but 1 is already in the hash, so add 2 to key 1
'Codewars'.hashify() == {"C":"o","o":"d","d":"e","e":"w","w":"a","a":"r","r":"s","s":"C"}

**/