Kata issue https://www.codewars.com/kata/5d653190d94b3b0021ec8f2b/discuss#5f7dc7dd51f6bc00336ea781

kata-issue.md

SPOILER ALERT

Kata issue: https://www.codewars.com/kata/5d653190d94b3b0021ec8f2b/discuss#5f7dc7dd51f6bc00336ea781

I get max call stack for this solution:

function productSum(a, m) {
  return calc(a, m, 0, 0, 1) % (1e9 + 7);
}

function calc(arr, k, i, subArrLen, subMul) {
  if (subArrLen === k) {
    return subMul;
  }
  
  if (i >= arr.length) {
    return 0;
  }
  
  return calc(arr, k, i + 1, subArrLen + 1, subMul * arr[i]) +
    calc(arr, k, i + 1, subArrLen, subMul);
}

Output:

 Random tests
 Test
RangeError: Maximum call stack size exceeded
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
    at calc
Completed in 64ms
Completed in 64ms