Question 422119 in Javascript Question posted in
A very good W3school tutorial can be found here.

Javascript – How to catch all errors that are thrown asyncronously in a Promise

The problem I am facing is that somewhere in the code I am working with there is an error that I cannot catch. The simplest example of this would be the code below:

try {
    new Promise((res, rej) => rej(new Error('You cannot catch me. Haha')));
} catch (err) {
    conosle.error(err);
}

Result in the console

I don’t want to alter the code much. I want to be able to catch and ignore some errors like that. I am trying to replace Promise by wrapping it so that i can catch all errors of that sort.

I have tried asking ChatGPT and it doesn’t help much, so Googling will most probably not help also.

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    After some fighting and effort I came up with this solution:

    const P = window.Promise;

const errorIgnorer = (err) => {
    if (err?.message?.includes('The play() request was interrupted by a call to pause()')
        || err?.message?.includes('Already in offline state')
        || err?.message?.includes('Pending connection was cancelled due to a disconnect request')) {
        return;
    }
    throw err;
};

function PromiseTemp(cb) {
    let promise = new P(cb);

    promise = promise.catch(errorIgnorer);

    function then(onFulfilled, onRejected) {
        const temp = P
            .prototype
            .then
            .call(
                this,
                onFulfilled,
                onRejected
            )
            .catch(errorIgnorer);

        temp.then = then;
        // eslint-disable-next-line @typescript-eslint/no-use-before-define
        temp.catch = catchFn;

        return temp;
    }

    function catchFn(onRejected) {
        const temp = then.call(this, null, onRejected);
        temp.then = then;
        temp.catch = catchFn;
        return temp;
    }

    promise.then = then;
    promise.catch = catchFn;

    return promise;
}

Object.setPrototypeOf(PromiseTemp.prototype, P.prototype);
Object.setPrototypeOf(PromiseTemp, P);

window['Promise'] = PromiseTemp as any;

    This solution catches all errors generated inside of promises and ignores errors that errorIgnorer function "filters".


  2. 0

    Promises have their own catch clause. You can catch it through that.

    try {
  new Promise((res, rej) => rej(new Error('You cannot catch me. Haha')))
             .catch(error => console.log("caught"));
} catch (err) {
    conosle.error(err);
}
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search