Promise Repeat

A simple utility that retries a given function until it either succeeds or certain failure criteria are met. It's also useful in case you want to just timeout a Promise.

I wrote this because I couldn't find a small library without dependencies for the purpose of including in a browser environment.

Installation

$ npm install promise-repeat

Usage

somePromiseFunction()
  .then(something )
  .then(promiseRepeat(fn, options))
  .then(...)
  .catch(...)

promiseRepeat(fn, options)() // note the trailing () which kicks-off the chain
  .then(...)
  .catch(...)

Options

Option	Default	Description
maxAttempts	3	Maximum number of attempts to make before failing
maxTimeout	3,000 (3 sec)	Maximum amount of time before the promsie gets rejected
throttle	0	How long to wait between calls to the function
throttleFn	returns throttle	function( retryCount, throttle ) - Custom throttle function to allow for timing adjustments
boolRetryFn	returns true	function( err, { retryCount: # }) - Function that should return true or false based on err as to whether or not the function should keep trying. Note that this does not override the maxRetries or maxTimeout options. Set those both to Infinity if you want to rely solely on this option.
resolveAfterReject		If the function returns a value after the promise has been rejected due to a timeout, this is called so that you can actually catch the result (in case you need to roll it back, notify user, etc). Potentially called once for each attempt at running the promise

If a promise is rejected it is rejected with the last error, with err.previousErrors = Error[] added to object