Promise retry

promise-retry.js

'use strict';

let i = 0;

const fn = () => {
    if (i++ < 5)
        throw new Error(`crap ${i}`);

    return "success";
};

const pfn = (resolve, reject) => {
    try {
        resolve(fn());
    } catch (ex) {
        console.log(ex);
        reject(ex);
    }
};

const ppfn = () => {
    return new Promise(pfn);
}

const retry = (retries, fn) => {
    return fn().catch((e) => {
        if (retries <= 0) {
            throw e;
        }

        console.log('retry attempt ' + retries + ' left');
        // return a promise from then(), the next then() will be on the returned promise 
        // http://stackoverflow.com/questions/27715275/whats-the-difference-between-returning-value-or-promise-resolve-from-then
        return retry(retries - 1, fn);
    });
};

retry(7, ppfn);