Из массива вида [0,1,2,3,4,5,6] нужно сделать [[1,2,3],[4,5,6]]

let inp = [0,1,2,3,4,5,6];
let out = [];
for (let i = 1, makeLine = true; i < inp.length; i++) {
  if (makeLine) {
    out.push([]);
    makeLine = !makeLine;
  }
  out[out.length - 1].push(inp[i]);
  if (out[out.length - 1].length == 3) {
    makeLine = true;
  }
}
console.log(JSON.stringify(out));