promise-retry-or-throw v1.0.5

promise-retry-or-throw

Simple wrapper for retrying a promise

Installation

$ npm install promise-retry-or-throw

Usage

import promiseRetry from 'promise-retry-or-throw';

promiseRetry(fn, options)

Call fn promise until it resolves or the maximum number of retries is reached (or the rejected promise matches a given early termination filter).

Options

• maxNumberOfRetries : Maximum number of attempts to be made before giving up. Default is 10
• delayIncrease : Time increase between each retry (in milliseconds). Default is 1000
• filter : An error filter to allow early termination, e.g. for unrecoverable errors. Default is () => false
• calculateDelay : A function for calculating the delay between each retry attempt. Default is to increment last delay by delayIncrease

Simplest use case:

const action = () => Promise.resolve(data);
promiseRetry(action)
  .then(response => assert.deepEqual(response, data));

Early termination

Some errors should be treated as unrecoverable and a retry should not be attempted. An optional filter function can be passed in which is expected to return a truthy value for an early termination.

const action = () => Promise.reject('test');

const options = {
  filter: (error) => error == 'test'
}

return promiseRetry(action, options)
  .then(() => {
    throw new Error('promiseRetry should not have resolved')
  })
  .catch(error => assert.equal(error, 'test'));

User defined delay strategy

const customDelayIncrease = ({delay, delayIncrease}) => {
  return delay * delayIncrease;
}

const options = {
  maxNumberOfRetries: 40
  delayIncrease: 10,
  calculateDelay: customDelayIncrease
};

return promiseRetry(action, options);