JS: reload module reference

index.js

let storage = require("./storage");

storage.add("hello");
console.log(storage.size()); // 1
storage.add("hello1");
console.log(storage.size()); // 2

storage = undefined;
delete require.cache[require.resolve("./storage")];

storage = require("./storage");
console.log(storage.size()); // 0

storage.js

const arr = [];

function add(value) {
  arr.push(value);
}

function size() {
  return arr.length;
}

exports.add = add;
exports.size = size;