Promise all properties


A helper function that receives an object with a [Promise] in each property and returns a promise that resolves to an object with the same properties and the resolved values of the promises.

The returned promise is rejected in the following cases:
1. The input argument is not an "object"
2. At least one of the promises are rejected

[Promise]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

Requirements

* ES6 Promise supporting Javascript engine (browser or Node.js), or at least an ES6 Promise polyfill
* a node package manager installed (such as NPM or Yarn)

Usage example (ES6/Typescript):

``javascript
import promiseAllProperties from 'promise-all-properties';

const promisesObject = {
someProperty: Promise.resolve('resolve value'),
anotherProperty: Promise.resolve('another resolved value'),
};

const promise = promiseAllProperties(promisesObject);

promise.then((resolvedObject) => {
console.log(resolvedObject);
// {
// someProperty: 'resolve value',
// anotherProperty: 'another resolved value'
// }
});

`

Promise all settled properties

This helper function works the same as promiseAllProperties, except it uses [Promise.allSettled][allSettled] instead of [Promise.all][all]. It is therefore possible to get the status of all the promises, regardless of how many of them were fulfilled or rejected.

Usage example:

`javascript
import {promiseAllSettledProperties} from 'promise-all-properties';

const promisesObject = {
someProperty: Promise.resolve('resolve value'),
anotherProperty: Promise.reject(new Error('a rejection')),
yetAnotherProperty: Promise.reject(new Error('another rejection')),
};

const promise = promiseAllSettledProperties(promisesObject);

promise.then((resolvedObject) => {
console.log(resolvedObject);
// {
// someProperty: {status: 'fulfilled', value: 'resolve value'},
// anotherProperty: {status: 'rejected', reason: Error('a rejection')},
// yetAnotherProperty: {status: 'rejected', reason: Error('another rejection')}
// }
});

// By comparison, promiseAllProperties(promisesObject) would reject with Error('a rejection')
`

[allSettled]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled
[all]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all

Breaking changes

$3

- Minimum Node.js version is now 12.20.0 to support the promiseAllSettledProperties method

$3

- Passing an Array of values causes the promise to be rejected as invalid
- Stricter TypeScript signature now errors on non-object arguments.

Developers

$3

`bash
npm test
`

$3

`bash
npm run build
`

$3

PR's are welcome just make sure the the PR is squashed (one commit) and the commit messages starts with one of the following prefixes:

[INITIAL]: The initial commit
[FEAT]: Only changes that creating new features or modofying existing features, that are not bug fixes
[FIX]: Only bug fixes
[DOCS]: Only Documentation changes
[STYLE]: Only changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
[REFACTOR]: Only code changes that are neither fixes or features
[TEST]: Only changes that are adding new tests or modifying existing tests
[TOOLS]: Only changes that affect external processeses like build tools, dev tools, auxiliary tools and libraries such as documentation generation
[CLEANUP]`: Only code removal: code lines, comment lines or files without affecting the project whatsoever

License

Public domain [Unlicense][unlicense]

[unlicense]: http://unlicense.org/