NodeJS：如何等待由 runInNewContext 调用的异步脚本？

Question

I'm attempting to execute a custom Script object using runInNewContext .

let myScript = (async () => {
  let response = await fetch('/article/promise-chaining/user.json');
  let user = await response.json();
})();

let vm = new Script(myScript, myScriptOptions);

let result = vm.runInNewContext(mySandbox, myContextOptions);
console.log("Done running!");

However, the problem I'm running into is that I'd like runInNewContext to actually wait until myScript 's asynchronous function is done running. In other words, I would like "Done running!" to be printed after the response has been fetched. Is this possible? How can I achieve it please?

Answer 1

You must:

1. Make your original function return a promise
2. Await that promise when calling runInNewContext .

Therefore, let's say you want to return the user object:

let myScript = (async () => {
  let response = await fetch('/article/promise-chaining/user.json');
  let user = await response.json();
  return user;
})();

Then, add await here

let result = await vm.runInNewContext(mySandbox, myContextOptions);

as if you try to print the value of result it will be a promise so adding await will do what you are trying to achieve