I know blocking the event loop is bad and the consequences of that. But even the native fs module provides some sync functions for some purposes, for example, CLIs using fs.readFileSync.

I'd like to convert the following async-await code to blocking code.

let value = undefined;

function setup() {
  return new Promise((resolve) => {
    setTimeout(() => {
      value = "**value**";
      resolve();
    });
  });
}

// need to convert below function to blocking
async function getValue() {
  await setup();
  return value;
}

console.log(await getValue()); // top level await OK

Assuming it is blocking, we can then call it like

getValue(); // without await or .then

I tried it like this. But it is not working.

function getValue() {
  setup();
  while (!value) {
    // wait until we get value
  }

  return value;
}

console.log(getValue())

How can I achieve this?

(The fs.readFileSync is blocking. Is there any way we can use the technique used by readFileSync)

Edit

Related thread: Convert asynchronous/callback method to blocking/synchronous method