CODEWITHSUNDEEP
javascriptnode.jsasync-await
clearzcreen19
clearzcreen19

Reputation: 111

Waiting for promise to fulfill in Node.js

I'm working on a project in Node.js that uses user certificates. I need to generate them synchronously, in a blocking manner, but the library I use (pem) has only asynchronous functions (callbacks). I tried multiple ways to tackle the problem, but none of my tries have been successful. My code looks like this:

function KeyObject(CN, serverKey, days = 365) { // key object
  if (typeof CN !== 'string' ||
    typeof days !== 'number' ||
    typeof serverKey !== 'object') {
    throw TypeError;
  }
  this.CN = CN;
  this.days = days;
  const _this = this;

  async function generatePrivate() {
    var p = new Promise((resolve, reject) => {
      pem.createPrivateKey((err, obj) => {
        if (err) reject(err);
        _this.private = obj.key;
        resolve();
      });
    });
    await p;
  }

  async function generateCert(serviceKey) {
    if (typeof serviceKey !== 'object') {
      throw TypeError;
    }
    var p = new Promise((resolve, reject) => {
      pem.createCertificate({
        commonName: _this.CN,
        days: _this.days,
        serviceKey: serviceKey.private
      }, (err, obj) => {
        if (err) reject(err);
        _this.cert = obj.certificate;
        resolve();
      });
    });
    await p;
  }
  // init the keys
  generatePrivate();
  generateCert(serverKey);
}

This code goes straight through and doesn't wait for the functions to complete. What should I do? Thanks in advance.

Upvotes: 1

Views: 695

Answers (1)

Daniel A. White
Daniel A. White

Reputation: 191058

You should just return the Promise from each of those functions - no need to await or make them async. You also can't have an async constructor, perhaps adding an async factory would work.

Upvotes: 1

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