ts_mutex

const shoppingCartMutex = new Mutex();

shoppingCartMutex.runExclusive(async () => {
  cart.add(items);
  total = await cart.calculateTotal();
});

shoppingCartMutex.runExclusive(async () => {
  await cart.applyCoupons();
  total = await cart.calculateTotal();
});

import { Mutex, ReleaseFunction } from "https://deno.land/x/ts_mutex/mod.ts";