Error in ASYNC update method with Node.js

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Unhandledpromiserejectionwarning: Unhandled Promise rejection. This error either originated by Throwing Inside of an async Function without a catch block, or by rejecting a Promise which was not handled with . catch().

when I try to run the async Node update method, I get this error message

node.js

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1 answer

3

This message means you have a Promise, which was rejected(an error occurred) and this error was not treated.

If you are dealing with Promises through functions async, you must add a Try...catch to capture the error of the function you called; and you need to treat this error.

Examples of how you might have received this error, given the function:

async function ruim() {
    throw new Error('Ops');
}

❌Erro1 - do not treat:

In the code below the error is not treated:

async function errado1(){
    await ruim();
}
errado1();

❌Erro2 - do not wait:

In the code below is not waiting for the execution of async function, then the error is not captured:

async function errado2(){
    try{
        ruim();
    } catch(e) {
      console.log('ocorreu um erro: ' + e);  
    }
}
errado2();

✅Correct:

async function correto(){
    try{
        await ruim();
    } catch(e) {
      console.log('ocorreu um erro: ' + e);  
    }
}
correto();

Note that this does not solve the error itself, it just corrects the handling of the exception.

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