A utility for easily repeating a promise-based task, until it succeeds. Works both in Node and in the browser.

Installation

``sh
$ npm install repeat-promise-until-resolved
`

Table of Contents

- Examples
* Usage
* Basic example
* Additional configuration
- API

Examples

#### Usage

In a node-based environment:

`javascript
const repeatPromiseUntilResolved = require('repeat-promise-until-resolved');

`

If you're using it in the browser, without any build system, simply expose it to the global object:
`html


`
 

#### Basic example

`javascript
const repeatPromiseUntilResolved = require('repeat-promise-until-resolved');
const axios = require('axios');

(async()=>{

//Create a function that returns a promise, which you want to repeat until resolved. If you're not familiar with async functions, note that they return a promise.
async function promiseFactory() {
const { data } = await axios('https://jsonplaceholder.typicode.com/todos/1')
console.log(data)
}

try {
//Pass the promise-producing function, and an optional config object. The default maxAttempts value is 3.
await repeatPromiseUntilResolved(promiseFactory, { maxAttempts: 3});//Will be performed 3 times at most, until it finally fails.
} catch (error) {//An error will be thrown, only after the final failing attempt.
console.log('final fail',error)
}
})()



`

 

#### Additional configuration

`javascript

(async()=>{
async function promiseFactory() {

const { data } = await axios('https://jsonplaceholder.typicode.com/todos/1')
console.log('success',data)
}

//Hook into each attempt, and receive the attempt number
const onAttempt = (attempt) => {
console.log(attempt);
}

//Hook into every error thrown, and receive the Error object and the attempt number.
const onError = (error, attempt) => {
console.log(error.message, attempt);
}

try {
//Limit to 5 attempts, and create a delay of 2 seconds between each attempt. timeout: Wait up to 5 seconds for each promise to resolve, until it's manually rejected(and retried)
//Also pass functions to the hooks.
await repeatPromiseUntilResolved(promiseFactory, { maxAttempts: 5, delay: 2000, timeout:5000, onAttempt, onError });
} catch (error) {
console.log('final fail',error)
}
})()


``


#### API

$3

| Parameter | type | Description |
| ----------- |---- | ------------------------------------------------------------ |
| promiseFactory | function | A function that returns the promise you want to "repeat" |
| config | object| A configuration and hook object. Not required|
| config.maxAttempts | number| Number of maximum attempts(including the first one) |
| config.delay | number| Number of milliseconds to wait between each retry. Useful in network requests |
| config.timeout | number| Number of milliseconds to wait, until the promise is manually rejected. Default is 8000 |
| config.onAttempt | function| Hook into each attempt. Receives the number of the current attempt as an argument |
| config.onError | function| Hook into each failed attempt. Receives the Error object as an argument |
| config.shouldStop | function| Hook into each failed attempt. Receives the Error object as an argument. Return true, if you want the repetition to stop |