async_local_storage_middleware.js

const { AsyncLocalStorage } = require("async_hooks");
const storageContext = new AsyncLocalStorage();

const middlewares = [];
function addMiddleware(callback) {
  middlewares.push(callback);
}

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

addMiddleware((next) => storageContext.run("hello world!", next));
addMiddleware((next) => {
  setTimeout(() => {
    console.log("set timeout middleware", storageContext.getStore());
    next();
  }, 10);
});
addMiddleware(async (next) => {
  await delay(100);
  console.log("after delay middleware", storageContext.getStore());
});
addMiddleware((next) => next());

function runMiddleware() {
  function runNext(i) {
    const cb = middlewares[i];
    cb(() => {
      if (i < middlewares.length - 1) runNext(i + 1);
    });
  }
  runNext(0);
}

runMiddleware();