monkey_patch_http_server.js

/* ------------ monkey patching  ------------ */
const http = require('http')

const originalServerEmit = http.Server.prototype.emit;
http.Server.prototype.emit = function (event) {
  if (event === 'request') {
    // setup the context here as the root of the execution tree
    setContext();
  }
  return originalServerEmit.apply(this, arguments)
};

/* ------------ business logic  ------------ */
async function even_more_nested_call() {
  console.log("nested in nested.", getContext());
}

async function nested_call() {
  console.log("nested call", getContext());
  await even_more_nested_call();
}

async function some_other_nested_call() {
  console.log("some other nested call", getContext());
}

async function do_work() {
  console.log("do some work", getContext());
  await nested_call();
  await some_other_nested_call();
}

const server = http.createServer(function (req, res) {
  do_work().then(() => {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.write('Hello World!');
    res.end();
  });
});

server.listen(8080);