2048-moveLineUp.js

2048-moveLine.js

const moveLineUp = (line) => {
  // Internal function to recursive
  const moveLineUpInner = (currentLine, results=[]) => {
    if (currentLine.length === 0) return results;

    if(currentLine[0] === currentLine[1]) {
      const total = currentLine[0] + currentLine[1];
      return moveLineUpInner(currentLine.slice(2), [...results, total]);
    }

    return moveLineUpInner(currentLine.slice(1), [...results, currentLine[0]]);
  };

  return arrayPad(moveLineUpInner(line.filter((n)=>n > 0)), line.length); // Array pad here
};