Promises-retry NPM

Promises Retry

Retry promises with exponential back-off strategy. Exit on custom logic before the maximum number of retries. No external dependencies used.

Installing

npm install promises-retry

Prerequisites

Works only on node >=7.6

If you want to test the module, you need to have mocha installed on your machine.

##Signature

retry(fn,options)

fn - anonymus function wrapper for a function that returns a promise
options - options object (refer below for in depth overview)

Usage

const retry = require('promises-retry');

Using default retry parameters:

async function(){
    try{
        //fn - function which returns a promise
        const result = await retry(()=> functionThatReturnsPromise() );
        //use the result
    } catch(err){
        //your promise failed to execute after the number of retries(by default 10)
    }
}

Using custom configuration:

async function(){
    try{
        const result = await retry(()=> functionThatReturnsPromise(), {
        retries:3,
        minTimeout:500,
        exit:(attempt,err) => {
            if(err.message='Your error message')
               return true;
            return false;
            }
        })
        //use the result
    } catch(err){
        //your promise failed to execute after the number of retries or using custom logic
    }
}

Available options parameters

retries - the number of retries for a promise(defaults to 5)
factor - the exponential factor to use(defaults to 2)
minTimeout - the number of milliseconds before starting a retry(defaults to 1000)
exit - function(attempt,err) utility function for implementing custom logic to exit retrying if some condition is fulfilled. Useful for implementing fast exit for a promise, for example if a connection times out.(defaults to false )