promise-retryer

provides an easy way to make promises retry based on exceptions or result validation

install

npm install promise-retryer

params

• delay (can be a number or function that returns a number, if its a function it gets called with an attempt argument)
• maxRetries (the maximum amount of retries)
• validate (validation promise)
• onError (callback function on errors, gets called with an error object and an attempt argument)
• onAttempt (callback function on attempts, gets called with an attempt argument)
• debug (enable verbose logging)
• name (this is useful for debugging purposes)

examples

heres a basic retry example

var PromiseRetryer = require('promise-retryer')(Promise);

PromiseRetryer.run({
	delay: 1000,
	maxRetries: 5,
	promise: function (attempt) {
		return makeAsyncRequest(); // returns a promise
	}
}).then(
	function (response) {
		console.log(response);
	},
	function (error) {
		console.log(error);
	}
);

and heres a little more advanced example with validation and custom delays

var PromiseRetryer = require('promise-retryer')(Promise);

PromiseRetryer.run({
	delay: function (attempt) {
		return attempt * 1000;
	},
	maxRetries: 5,
	promise: function (attempt) {
		return makeAsyncRequest(); // returns a promise
	},
	validate: function (response, attempt) {
		return new Promise(function (resolve, reject) {
			if (typeof response === 'object') {
				resolve(response);
			} else {
				reject(new Error('response was not an object'));
			}
		});
	}
}).then(
	function (response) {
		console.log(response);
	},
	function (error) {
		console.log(error);
	}
);