[JavaScript] Max compartment finding

compartment.js

const assert = require("assert");

// S is a compartment.
// * is an Item
// We want to count how many item exists in closed compartment.
// Closed compartment means in range like as;
// s = "*|*|*|***|";
// 1, 3 => *|* = any item exists in closed compartment
// 1, 5 => *|*|*|* = 1 item exists in closed compartment.

function numberOfItems(s, startIndicies /* [1, 1] */, endIndicies /* [3, 10] */) {
  let calculated = []
  
  // console.log("INPUT: ", s, startIndicies, endIndicies)
  
  /* S = *|*|*|***|*|*|*|***|*|*|*|***|*|*|*|***|*|*|*|***|*|*|*|***| */
  for (let i = 0; i < startIndicies.length; i++) {
    const sub = s.substr(startIndicies[i] - 1, endIndicies[i]);
    let left = 0, right = sub.length;

    while (left != sub.length && sub[left] != "|")
      left++;

    while (right != 0 && sub[right] != "|")
      right--;
    
    // console.log("SUB: ", sub, sub.length)
    // console.log("RANGE: ", left, right)

    let count = 0
    while (left != right)
      count += (sub[left++] == "*")

    // console.log("COUNT: ", count)
    calculated.push(count)
  }

  return calculated;
}

var s = "*|*|*|***|";
var startIndices = [1, 1];
var endIndices = [3, 10];
var expected = [0, 5];
assert.deepStrictEqual(numberOfItems(s, startIndices, endIndices), expected);

var s = "*|*|**|**|*|*|**|**|*|*|**|**|*|*|**|**|";
var startIndices = [1, 22, 5, 6, 7];
var endIndices = [5, 25, 14, 29, 8];
var expected = [1, 11, 6, 16, 4];
assert.deepStrictEqual(numberOfItems(s, startIndices, endIndices), expected);

s = "*|*|**|**|*|*|**|**|*|*|**|**|*|*|**|**|";
var startIndices = [1, 22, 5, 6, 7];
var endIndices = [5, 25, 14, 29, 8];
var expected = [1, 11, 6, 16, 4];
assert.deepStrictEqual(numberOfItems(s, startIndices, endIndices), expected);

s = "";
var startIndices = [1];
var endIndices = [999999999999999999999999999999999];
var expected = [0];
assert.deepStrictEqual(numberOfItems(s, startIndices, endIndices), expected);