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Wait until all promises have completed even when some reject, with Promise.all
var a = ["sdfdf", "http://oooooolol"],
handleNetErr = function(e) { return e };
Promise.all(fetch('sdfdsf').catch(handleNetErr), fetch('http://invalidurl').catch(handleNetErr))
.then(function(sdf, invalid) {
console.log(sdf, invalid) // [Response, TypeError]
})
.catch(function(err) {
console.log(err);
})
Promise.all(a.map(function(e) {
return fetch(e).catch(handleNetErr)
})).then(function(e) {
console.log('then',e) // Outputs: 'then', [Response, TypeError]
}).catch(function(e) {
console.log('err',e)
})
let a = new Promise((res, rej) => res('Resolved!')),
b = new Promise((res, rej) => rej('Rejected!')),
c = a.catch(e => { console.log('"a" failed.'); return e; }),
d = b.catch(e => { console.log('"b" failed.'); return e; });
Promise.all([c, d])
.then((first, second) => console.log('Then', first, second)) // Then ["Resolved!", "Rejected!"]
.catch(err => console.log('Catch', err));
Promise.all([a.catch(e => e), b.catch(e => e)])
.then((first, second) => console.log('Then', first, second)) // Then ["Resolved!", "Rejected!"]
.catch(err => console.log('Catch', err));
@mariojunior

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mariojunior commented Apr 24, 2017

Thanks a lot. I've found your script when I was almost giving up and adding another lib to handle my promise. 👍

@yardensk

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yardensk commented Oct 17, 2017

nice

@andrei-cacio

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andrei-cacio commented Oct 26, 2017

kudos! Was looking for a solution like this

@titusjin

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titusjin commented Dec 23, 2017

awesome!! Thanks lots

@Argo-92

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Argo-92 commented Feb 8, 2018

This was a great solution!

@scagood

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scagood commented Mar 12, 2018

Promise.almost = r => Promise.all(r.map(p => p.catch ? p.catch(e => e) : p));

I added the 'almost' prototype to my promises, using this technique, nice solution.

@enapupe

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enapupe commented Jul 16, 2018

@scagood that's beautiful and very useful, ty

@john-doherty

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john-doherty commented Aug 19, 2018

Great. Thanks!

@toritsejuFO

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toritsejuFO commented Sep 12, 2018

Sweet! 😁

@NishiJain91

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NishiJain91 commented Oct 23, 2018

Thanks. This should be inbuilt in ES6.

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