Extension for Promises which gets the result of the first Promise that passes

Promise.first

/**
 * Promise.first
 * Get the result of the first Promise that passes
 * If none of the Promises pass then it is rejected
 * Doesn’t short-circuit like Promise.race
 * Requires ES6
 */
if (Promise.first === undefined) {
    Promise.first = (promises) => {

        return new Promise((resolve, reject) => {
            var counter = 0;
            var result;

            var done = function(err, value) {
                counter++;

                if (value && result === undefined) {
                    result = value;
                }

                if (counter === promises.length) {
                    if (result) {
                        return resolve(result);
                    }

                    reject(err);
                }
            }

            for (var promise of promises) {
                promise.then((value) => {
                    done(null, value)
                }, (reason) => {
                    done(reason);
                });
            }
        });
    };
}