如何在 Promise 捕获块中引发异常？ （未处理的 promise 拒绝）

Question

I have a multiple functions that return a Promise. In case of an error they use reject . But I want to handle the errors in the catch block of Promise.all() call. But when running it causes an Unhandled promise rejection .

function errorFunc() {
    return new Promise((_, reject) {
    reject('rejected in errorFunc')
  })
}

Promise.all([
    errorFunc(),
]).catch(reasons => {
    //throw new Error('an error occured', reasons)
  console.log('an error occured')
})

As you can see the console.log works fine, but running when throwing an exception it fails. I have read multiple articles and threads on unhandled promise rejection but I have not found a solution to that problem.

Here is the failing code on JSFiddle: https://jsfiddle.net/qkptbjnz/1/

How do I solve this issue? Or do you have a suggestion for a better error handling?

Edit I want to achieve some kind of validation like here: https://jsfiddle.net/89d5nLcw/

Answer 1

Well, you should not throw an error in catch section, this block is designed to handle the errors.

 function errorFunc() { return new Promise((_resolve, reject) => { reject('rejected in errorFunc'); }); } Promise.all([ errorFunc(), ]).catch(error => { console.log('an error occured', error); })

like here you can see the message you threw above.