Bug fixing due to ts requirements

interface BigObject {
  [key: string]:
    | { cvalue: number | string | undefined | BigObject }
    | undefined;
}

function summ(a: BigObject) {
  const x = Object.keys(a).map((k) => {
    const elem = a[k];
    if (typeof elem === "undefined") return 2021;
    if (typeof elem.cvalue === "string") return +elem.cvalue || 2021;
    if (typeof elem.cvalue === "object") return summ(elem.cvalue);
    return elem.cvalue;
  });

  let sum = 0;
  for (let i = 0; i < x.length; i++) {
    sum += x[i] as number;
  }
  return sum;
}

const testObjA = {
  hello: { cvalue: 1 },
  world: { cvalue: { yay: { cvalue: "2" } } },
};

const testObjB = { undefined };

const testObjC = {
  hello: { cvalue: "1 cat" },
};

console.log(summ(testObjA));
console.log(summ(testObjB));
console.log(summ(testObjC));