Timeout async/await functions after a few seconds

Question

I created a function to get an Oracle connection using oracledb, but in a few cases, oracledb didn't throw an exception even if he didn't get the connection, apparently he's trying to connect infinitely.

const getConnection = async (): Promise<oracledb.Connection | undefined> => {
  let connection;

  try {
    connection = await oracledb.getConnection({
      user: process.env.DB_LOGIN,
      password: process.env.DB_PASSWORD,
      connectString: process.env.DB_STRING_CONNECTION,
    });
  } catch (err) {
    console.error(err);
  }
  return connection;
};

I saw a few samples using Promise.racing with setTimeout but i couldn't put it in pratice, my tries always get an UnhandledPromiseRejectionWarning on console so i think it isn't the correct way.

Can anybody show me an example how to do that?

Answer 1

Promise.race should work fine if you implement it properly. Race the getConnection against a Promise that resolves (not rejects), and make sure to chain to a .catch.

const getConnection = (): Promise<oracledb.Connection | undefined> => {
    return Promise.race([
        oracledb.getConnection({
            user: process.env.DB_LOGIN,
            password: process.env.DB_PASSWORD,
            connectString: process.env.DB_STRING_CONNECTION,
        }),
        new Promise((resolve) => { setTimeout(resolve, 5000); })
    ])
        .catch((error) => {
            // this will only be entered into if getConnection rejects (and not if it times out)
            console.log(error);
        })
};