retrying-promise

Create fault tolerant promises that retry upon failure according to a retry strategy.

The implementation of the retry strategies reuses code from the node-retry project.

Usage

Install retrying-promise:

npm install retrying-promise

Import retrying-promise:

const retryPromise = require('retrying-promise');

The constant retryPromise is a function that returns a promise. Use this function similar to how you call the new Promise() constructor, but pass it a function that takes three instead of two functions as arguments: resolve, retry and reject.

var promise = retryPromise(function (resolve, retry, reject) {

    resolve(result);  // the promise resolves normally

    retry(error);     // the promise failed and a retry may be attempted

    reject(error);    // the promise failed and no retry should be attempted

});

Call the resolve function when the promise resolves normally.

Call the retry function when the promise failed and a retry may be attempted.

Call the reject function when the promise failed and no retry should be attempted.

Test

Install Mocha.

sudo npm install -g mocha

Run tests:

npm test

API Reference

Author: Wouter Van den Broeck
Copyright: 2016

module.exports([options], executor) ⇒ `Promise` ⏏

Returns a promise that conditionally tries to resolve multiple times, as specified by the retry policy.

Kind: Exported function

Param	Type	Description
[options]	`retryPolicy`	Either An object that specifies the retry policy.
executor	`retryExecutor`	A function that is called for each attempt to resolve the promise.

module.exports~createTimeout(attempt, opts) ⇒ `number`

Get a timeout value in milliseconds.

Kind: inner method of module.exports
Returns: number - The timeout value in milliseconds.

Param	Type	Description
attempt	`number`	The attempt count.
opts	`Object`	The options.

module.exports~retryPolicy : `Object`

An object that specifies the retry policy.

Kind: inner typedef of module.exports
Properties

Name	Type	Default	Description
retries	`number`	`10`	The maximum amount of times to retry the operation.
factor	`number`	`2`	The exponential factor to use.
minTimeout	`number`	`1000`	The number of milliseconds before starting the first retry.
maxTimeout	`number`	`Infinity`	The maximum number of milliseconds between two retries.
randomize	`boolean`	`false`	Randomizes the timeouts by multiplying with a factor between 1 to 2.

module.exports~retryExecutor : `function`

The function that is called for each attempt to resolve the promise.

Kind: inner typedef of module.exports

Param	Type	Description
resolveFn	`function`	To be called when the promise resolves normally.
retryFn	`function`	To be called when the promise failed and a retry may be attempted.
[rejectFn]	`function`	To be called when the promise failed and no retry should be attempted.

Package detail