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https://github.com/arikw/flat-promise
Create a fresh new Promise with exposed 'resolve' & 'reject' callbacks available outside of its executor function
https://github.com/arikw/flat-promise
javascript promise
Last synced: about 2 months ago
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Create a fresh new Promise with exposed 'resolve' & 'reject' callbacks available outside of its executor function
- Host: GitHub
- URL: https://github.com/arikw/flat-promise
- Owner: arikw
- License: mit
- Created: 2018-11-19T11:56:51.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2024-06-16T11:12:08.000Z (8 months ago)
- Last Synced: 2024-11-11T20:55:24.740Z (3 months ago)
- Topics: javascript, promise
- Language: JavaScript
- Homepage:
- Size: 44.9 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Flat Promise
Create a fresh new `Promise` with exposed `resolve()` & `reject()` callbacks available outside of its executor function
# Installation
```sh
npm install flat-promise
```
# Usage
```js
const flatPromise = require("flat-promise");
```
# Examples
## Basic usage ##
`flatPromise()` will return an object containing a new `Promise` and its `resolve()` and `reject()` methods.
### Creating an instance ###
```js
const { resolve, reject, promise } = flatPromise();
```
It's recommended to avoid giving the control of the promise (the resolution methods) beyond the outer scope of where the promise was created - don't return `resolve()` or `reject()` methods nor keep a reference to the methods in an outer scope.
### Usage example ###
```js
function doAsyncWork() {
// Get your promise and resolution methods
const { promise, resolve, reject } = flatPromise();
// Do something amazing...
setTimeout(() => {
resolve('done!');
}, 500);
// Pass your promise to the world
return promise;
}
const result = await doAsyncWork();
console.log(result);
```
## Alternative usage ##
`flatPromise.withControl()` will return a promise with its resolution methods exposed inside it. It means passing around the promise is also passing around its `resolve()` and `reject()` methods.
The `then()`, `catch()` & `finally()` methods also return a promise containing `resolve()` and `reject()` methods.
***Notice: This usage makes the promise state harder to maintain and to control.***
### Creating an instance ###
```js
const promise = flatPromise.withControl();
```
*- or -*
```js
const { promise, resolve, reject } = flatPromise.withControl();
```
### Usage example ###
```js
function doAsyncWork() {
// Get your promise and resolution methods
const promise = flatPromise.withControl().then(() => "cool!");
// Do something amazing...
setTimeout(() => {
promise.resolve();
}, 500);
// Pass your promise (and control!) to the world
return promise;
}
const result = await doAsyncWork();
console.log(result);
```
# Caveat
This library basically brings a way to fulfill or reject a promise outside the promise chain. It means that errors thrown in the process of promise settling will not automatically reject the promise and should be catched explicitly!
Please see [this great explanation](https://stackoverflow.com/questions/28687566/#28692824) for more information about throw safety.