oh-no-i-insist

Oh, no, I insist

Flexible retry for JavaScript promises. Supports native Promises and 3rd party A+ Promise libraries.

Installation

Install using NPM

npm install oh-no-i-insist -S

Usage

 retry(promiseGenerator, delay, maxTimes, predicate, onRetry, PromiseImplementation)

• promiseGenerator: function that should return a Promise you want to retry. Will be invoked once per each try.
• delay: int number of milliseconds between retries
• maxTimes: int the number of times to retry
• predicate: function (error) optional a function executed to check if the error is retriable. It will receive the error/rejection reason, and should return true if it is retriable. Return false to break the retry chain.
• onRetry: function optional a function that will be executed before waiting for each retry, but not before the first try. Use this to clean up resources, tell the user that you're waiting for a retry and things like that
• PromiseImplementation: class optional if working with an older Node.js implementation, the 3rd party Promise implementation that you want to use. If working with a more recent Node.js version and you want to use the native Promise, don't supply this argumenrt

Example

var retry = require('oh-no-i-insist'),
  generator = function() { 
    return new Promise(function (resolve, reject) { 
      var x = Math.random();
      if (x < 0.3) { 
        resolve(x);
      } else {
        reject(x);
      } 
    }); 
  }, shouldRetry = function (number) {
    console.log('got wrong', number);
    return number > 0.6;
  }, onRetry = function () {
    console.log('waiting for retry');
  };

retry(generator, 100, 5, shouldRetry, onRetry).then(function (num) {
  console.log('generated', num);
}, function (err) {
  console.log('failed with', err);
});

License

MIT