NEW ANSWER

const results = await Promise.all(promises.map(p => p.catch(e => e))); const validResults = results.filter(result => !(result instanceof Error)); 

FUTURE Promise API

• Chrome 76: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled
• You can download https://www.npmjs.com/package/promise.allsettled to get it now. In certain browsers allSettled comes preinstalled with the browser itself. It's worth downloading the package for peace of mind because eg. TypeScript doesn't have default definitions for allSettled.

ES2020 introduces new method for the Promise type: Promise.allSettled().

Promise.allSettled gives you a signal when all the input promises are settled, which means they’re either fulfilled or rejected. This is useful in cases where you don’t care about the state of the promise, you just want to know when the work is done, regardless of whether it was successful.

(async () => { const promises = [ Promise.resolve('success'), // succeeds Promise.reject('fails'), // fails ]; const result = await Promise.allSettled(promises); console.log(result.map(promise => promise.status)); // ['fulfilled', 'rejected'] })();

Read more in the v8 blog post.

Promise.allSettled

Instead of Promise.all use Promise.allSettled which waits for all promises to settle, regardless of the result

let p1 = new Promise(resolve => resolve("result1")); let p2 = new Promise( (resolve,reject) => reject('some troubles') ); let p3 = new Promise(resolve => resolve("result3")); // It returns info about each promise status and value Promise.allSettled([p1,p2,p3]).then(result=> console.log(result));

Polyfill

if (!Promise.allSettled) { const rejectHandler = reason => ({ status: 'rejected', reason }); const resolveHandler = value => ({ status: 'fulfilled', value }); Promise.allSettled = function (promises) { const convertedPromises = promises .map(p => Promise.resolve(p).then(resolveHandler, rejectHandler)); return Promise.all(convertedPromises); }; }

To continue the Promise.all loop (even when a Promise rejects) I wrote a utility function which is called executeAllPromises. This utility function returns an object with results and errors.

The idea is that all Promises you pass to executeAllPromises will be wrapped into a new Promise which will always resolve. The new Promise resolves with an array which has 2 spots. The first spot holds the resolving value (if any) and the second spot keeps the error (if the wrapped Promise rejects).

As a final step the executeAllPromises accumulates all values of the wrapped promises and returns the final object with an array for results and an array for errors.

Here is the code:

function executeAllPromises(promises) { // Wrap all Promises in a Promise that will always "resolve" var resolvingPromises = promises.map(function(promise) { return new Promise(function(resolve) { var payload = new Array(2); promise.then(function(result) { payload[0] = result; }) .catch(function(error) { payload[1] = error; }) .then(function() { /* * The wrapped Promise returns an array: * The first position in the array holds the result (if any) * The second position in the array holds the error (if any) */ resolve(payload); }); }); }); var errors = []; var results = []; // Execute all wrapped Promises return Promise.all(resolvingPromises) .then(function(items) { items.forEach(function(payload) { if (payload[1]) { errors.push(payload[1]); } else { results.push(payload[0]); } }); return { errors: errors, results: results }; }); } var myPromises = [ Promise.resolve(1), Promise.resolve(2), Promise.reject(new Error('3')), Promise.resolve(4), Promise.reject(new Error('5')) ]; executeAllPromises(myPromises).then(function(items) { // Result var errors = items.errors.map(function(error) { return error.message }).join(','); var results = items.results.join(','); console.log(`Executed all ${myPromises.length} Promises:`); console.log(`— ${items.results.length} Promises were successful: ${results}`); console.log(`— ${items.errors.length} Promises failed: ${errors}`); });

As @jib said,

Promise.all is all or nothing.

Though, you can control certain promises that are "allowed" to fail and we would like to proceed to .then.

For example.

 Promise.all([ doMustAsyncTask1, doMustAsyncTask2, doOptionalAsyncTask .catch(err => { if( /* err non-critical */) { return } // if critical then fail throw err }) ]) .then(([ mustRes1, mustRes2, optionalRes ]) => { // proceed to work with results }) 

Using Async await -

here one async function func1 is returning a resolved value, and func2 is throwing a error and returning a null in this situation, we can handle it how we want and return accordingly.

const callingFunction = async () => { const manyPromises = await Promise.all([func1(), func2()]); console.log(manyPromises); } const func1 = async () => { return 'func1' } const func2 = async () => { try { let x; if (!x) throw "x value not present" } catch(err) { return null } } callingFunction(); 

Output is - [ 'func1', null ]

if you get to use the q library https://github.com/kriskowal/q it has q.allSettled() method that can solve this problem you can handle every promise depending on its state either fullfiled or rejected so

existingPromiseChain = existingPromiseChain.then(function() { var arrayOfPromises = state.routes.map(function(route){ return route.handler.promiseHandler(); }); return q.allSettled(arrayOfPromises) }); existingPromiseChain = existingPromiseChain.then(function(arrayResolved) { //so here you have all your promises the fulfilled and the rejected ones // you can check the state of each promise arrayResolved.forEach(function(item){ if(item.state === 'fulfilled'){ // 'rejected' for rejected promises //do somthing } else { // do something else } }) // do stuff with my array of resolved promises, eventually ending with a res.send(); }); 

Promise.allSettled with a filter

const promises = [ fetch('/api-call-1'), fetch('/api-call-2'), fetch('/api-call-3'), ]; // Imagine some of these requests fail, and some succeed. const resultFilter = (result, error) => result.filter(i => i.status === (!error ? 'fulfilled' : 'rejected')).map(i => (!error ? i.value : i.reason)); const result = await Promise.allSettled(promises); const fulfilled = resultFilter(result); // all fulfilled results const rejected = resultFilter(result, true); // all rejected results 

For those using ES8 that stumble here, you can do something like the following, using async functions:

var arrayOfPromises = state.routes.map(async function(route){ try { return await route.handler.promiseHandler(); } catch(e) { // Do something to handle the error. // Errored promises will return whatever you return here (undefined if you don't return anything). } }); var resolvedPromises = await Promise.all(arrayOfPromises); 

Have you considered Promise.prototype.finally()?

It seems to be designed to do exactly what you want - execute a function once all the promises have settled (resolved/rejected), regardless of some of the promises being rejected.

From the MDN documentation:

The finally() method can be useful if you want to do some processing or cleanup once the promise is settled, regardless of its outcome.

The finally() method is very similar to calling .then(onFinally, onFinally) however there are couple of differences:

When creating a function inline, you can pass it once, instead of being forced to either declare it twice, or create a variable for it.

A finally callback will not receive any argument, since there's no reliable means of determining if the promise was fulfilled or rejected. This use case is for precisely when you do not care about the rejection reason, or the fulfillment value, and so there's no need to provide it.

Unlike Promise.resolve(2).then(() => {}, () => {}) (which will be resolved with undefined), Promise.resolve(2).finally(() => {}) will be resolved with 2. Similarly, unlike Promise.reject(3).then(() => {}, () => {}) (which will be fulfilled with undefined), Promise.reject(3).finally(() => {}) will be rejected with 3.

== Fallback ==

If your version of JavaScript doesn't support Promise.prototype.finally() you can use this workaround from Jake Archibald: Promise.all(promises.map(p => p.catch(() => undefined)));

We can handle the rejection at the individual promises level, so when we get the results in our result array, the array index which has been rejected will be undefined. We can handle that situation as needed, and use the remaining results.

Here I have rejected the first promise, so it comes as undefined, but we can use the result of the second promise, which is at index 1.

const manyPromises = Promise.all([func1(), func2()]).then(result => { console.log(result[0]); // undefined console.log(result[1]); // func2 }); function func1() { return new Promise( (res, rej) => rej('func1')).catch(err => { console.log('error handled', err); }); } function func2() { return new Promise( (res, rej) => setTimeout(() => res('func2'), 500) ); }

const promise1 = Promise.resolve(3); const promise2 = new Promise((resolve, reject) => setTimeout(reject, 100, 'foo')); const promises = [promise1, promise2]; let sum = 0; let promiseErrorArr = []; Promise.allSettled(promises) .then((results) => { results.forEach(result => { if (result.status === "rejected") { sum += 1; promiseErrorArr.push(result) } }) return ( (sum>0) ? promiseFailed() : promisePassed()) }) function promiseFailed(){ console.log('one or all failed!') console.log(promiseErrorArr) } function promisePassed(){ console.log('all passed!') } // expected output: // "one or all failed!" // Array [Object { status: "rejected", reason: "foo" }] 

With the help of allSettled,we can now read the status of each promise is, and process each error individually, without losing any of this critical information

const promises = [ fetch('/api/first'), // first fetch('/api/second') // second ]; 

The simplest way is to handle errors

const [firstResult, secondResult] = await Promise.allSettled(promises) // Process first if (firstResult.status === 'rejected') { const err = firstResult.reason // Here you can handle error } else { const first = firstResult.value } // Process second if (secondResult.status === 'rejected') { const err = secondResult.reason // Here you can handle error } else { const second = secondResult.value } 

A nice way to handle error

const results = await Promise.allSettled(promises); const [first, second] = handleResults(results) function handleResults(results) { const errors = results.filter(result => result.status === 'rejected').map(result => result.reason) if (errors.length) { // Aggregate all errors into one throw new AggregateError(errors) } return results.map(result => result.value) } 

Alternately, if you have a case where you don't particularly care about the values of the resolved promises when there is one failure but you still want them to have run, you could do something like this which will resolve with the promises as normal when they all succeed and reject with the failed promises when any of them fail:

function promiseNoReallyAll (promises) { return new Promise( async (resolve, reject) => { const failedPromises = [] const successfulPromises = await Promise.all( promises.map( promise => promise.catch(error => { failedPromises.push(error) }) ) ) if (failedPromises.length) { reject(failedPromises) } else { resolve(successfulPromises) } } ) } 

You can always wrap your promise returning functions in a way that they catches failure and returning instead an agreed value (e.g. error.message), so the exception won't roll all the way up to the Promise.all function and disable it.

async function resetCache(ip) { try { const response = await axios.get(`http://${ip}/resetcache`); return response; }catch (e) { return {status: 'failure', reason: 'e.message'}; } } 

I've found a way (workaround) to do this without making it sync.

So as it was mentioned before Promise.all is all of none.

so... Use an enclosing promise to catch and force resolve.

 let safePromises = originalPrmises.map((imageObject) => { return new Promise((resolve) => { // Do something error friendly promise.then(_res => resolve(res)).catch(_err => resolve(err)) }) }) }) // safe return Promise.all(safePromises) 

You would need to know how to identify an error in your results. If you do not have a standard expected error, I suggest that you run a transformation on each error in the catch block that makes it identifiable in your results.

try { let resArray = await Promise.all( state.routes.map(route => route.handler.promiseHandler().catch(e => e)) ); // in catch(e => e) you can transform your error to a type or object // that makes it easier for you to identify whats an error in resArray // e.g. if you expect your err objects to have e.type, you can filter // all errors in the array eg // let errResponse = resArray.filter(d => d && d.type === '<expected type>') // let notNullResponse = resArray.filter(d => d) } catch (err) { // code related errors } 

Not the best way to error log, but you can always set everything to an array for the promiseAll, and store the resulting results into new variables.

If you use graphQL you need to postprocess the response regardless and if it doesn't find the correct reference it'll crash the app, narrowing down where the problem is at

const results = await Promise.all([ this.props.client.query({ query: GET_SPECIAL_DATES, }), this.props.client.query({ query: GET_SPECIAL_DATE_TYPES, }), this.props.client.query({ query: GET_ORDER_DATES, }), ]).catch(e=>console.log(e,"error")); const specialDates = results[0].data.specialDates; const specialDateTypes = results[1].data.specialDateTypes; const orderDates = results[2].data.orders; 

Unfortunately, I don't have enough reputation to comment (or do much of anything, really), so I'm posting this as an answer in response to Eric's answer here.

The executor function can also be an async function. However, this is usually a mistake, for a few reasons:

• If an async executor function throws an error, the error will be lost and won’t cause the newly-constructed Promise to reject. This could make it difficult to debug and handle some errors.
• If a Promise executor function is using await, this is usually a sign that it is not actually necessary to use the new Promise constructor, or the scope of the new Promise constructor can be reduced.

From this explanation as to why Promises should not utilize an async executor function

Instead, you should opt for Promise.allSettled(), as suggested here by Asaf.

That's how Promise.all is designed to work. If a single promise reject()'s, the entire method immediately fails.

There are use cases where one might want to have the Promise.all allowing for promises to fail. To make this happen, simply don't use any reject() statements in your promise. However, to ensure your app/script does not freeze in case any single underlying promise never gets a response, you need to put a timeout on it.

function getThing(uid,branch){ return new Promise(function (resolve, reject) { xhr.get().then(function(res) { if (res) { resolve(res); } else { resolve(null); } setTimeout(function(){reject('timeout')},10000) }).catch(function(error) { resolve(null); }); }); }