allfulfilled

allfulfilled is a Node.js package for using Promise.allSettled like Promise.all.

Install

Install using npm:

npm install --save allfulfilled

Usage

allFulfilled(promises[, toError])

Returns a new Promise that is fulfilled with an array of fulfillment values when all the specified promises are fulfilled, or rejected with an Error if any of promises are rejected.

This function behaves similarly to Promise.all but uses Promise.allSettled internally to collect all rejection reasons before rejecting with a single Error.

Optionally, toError can be specified to reduce all rejection reasons to a single Error. Defaults to aggregate, which reduces all rejection reasons into an AggregateError.

Examples

import { allFulfilled, first } from "allfulfilled";

await allFulfilled([Promise.resolve(1), Promise.resolve("2"), Promise.resolve(3)]);
//=> [1, "2", 3]
await allFulfilled([Promise.resolve(1), Promise.reject(new Error("Oops")), Promise.resolve(3)]);
//=> AggregateError
await allFulfilled([Promise.resolve(1), Promise.reject(new Error("Oops")), Promise.resolve(3)], first());
//=> Error

ReasonsErrorReducer(reasons)

Reduces all reasons that any Promise was rejected with to a single Error.

A ReasonsErrorReducer is only called with a non-empty array of reasons.

There are a several ReasonsErrorReducer function providers built-in.

aggregate([message])

Returns a ReasonsErrorReducer that reduces all the reasons a Promise was rejected with into an AggregateError.

Optionally, message can be specified for the AggregateError.

any([toError])

Returns a ReasonsErrorReducer that returns any reason a Promise was rejected with as an Error, with a preference of using the first reason that is an Error to avoid calling toError, if specified.

If toError is specified and the every reason is not an Error, toError will be used to map the first reason to an Error.

first([toError])

Returns a ReasonsErrorReducer that returns the first reason a Promise was rejected with as an Error.

If toError is specified and the first reason is not an Error, toError will be used to map the first reason to an Error.

last([toError])

Returns a ReasonsErrorReducer that returns the last reason a Promise was rejected with as an Error.

If toError is specified and the last reason is not an Error, toError will be used to map the last reason to an Error.

Bugs

If you have any problems with this package or would like to see changes currently in development, you can do so here.

Contributors

If you want to contribute, you're a legend! Information on how you can do so can be found in CONTRIBUTING.md. We want your suggestions and pull requests!

A list of all contributors can be found in AUTHORS.md.

License

Copyright © 2026 neocotic

See LICENSE.md for more information on our MIT license.