Repeat chars single bigger sequences - JavaScript

single_sequences_equal_chars.js

/**
* Returns the sequences of repeated subsequence chars
* Example 1: 'Niiiiiiiceee' will return ['iiiiiii', 'eee']
* Example 2: 'NiiiiiiiceeeNiccceeeeeeeeeee' will return ['iiiiiii', 'ccc', 'eeeeeeeeeee']
*
* Notice that in 'Example 2', the 'e'char sequence that is returned is the second one, because it's bigger than the first one.
*/
const singleSequencesEqualChars = function(word) {
    let counter,
        checkedChars = [],
        result = {};
    
    if(word.length == 0) {
      return null;
    }
    
    result = {};
  
    for(let i = 0; i < word.length; i++) {
      counter = 0;
  
      for(let j = i; j < word.length; j++) {
        let currentChar = word.charAt(i);
        let nextChar = word.charAt(j);
        let charMissing = checkedChars.indexOf(currentChar) === -1;
        
        if(currentChar === nextChar) {
          counter++;
  
          let foundBiggerSequence = (result[currentChar] || '').length < counter;
          
          if(counter > 1 && (charMissing || foundBiggerSequence)) {
            result[currentChar] = ''.padStart(counter, currentChar);
          } 
        } else {
          checkedChars.push(currentChar);
          break;
        }
      }
    }
    const values = Object.values(result);
    console.log(values);
    return values.length === 0 ? null : values;
  }