Using Node Js Utility.promisify() Call Is Not Coming Back From Async Callback Method

I am trying to use node js promisify to convert the callback to promise inoreder to use await on a async callback function. I tried different ways to pass the parameter and put log

Solution 1:

I think a very small change should fix this.

If we want to pass console.log as a parameter we need to declare it separately in the callbackFn function.

The key point here is that we shouldn't pass the last callback to a promisified function when we call it, this will be handled for us.

We won't log exactly what you wish, because result will not be null.

We'll log:

31null'mayank IBM'2result: mayank IBM

Updated code:

const {promisify} = require('util');
constcallbackFn = (firstName, logCallback, callback) => {

setTimeout(() => {
    console.log("1");
    if (!firstName)  callback(newError('no first name passed in!'),null)

    const fullName = `${firstName} IBM`logCallback(null,fullName)
    callback(null,fullName)

}, 2000)
}

asyncfunctionuseAwaitEx(){
try {
    var calbbackfnpromisfied = promisify(callbackFn);
    console.log("3");
    var result = awaitcalbbackfnpromisfied('mayank', console.log);
    console.log("2");
    console.log("result:", result)

// console.log("result"+result)
}catch (error) {
    console.log("error"+error);
}
}
useAwaitEx();