feat: await-able Async methods (#1572)

* make each and family awaitable

* dont pretend they're AsyncFunctions

* check errors

* ensure function name is preserved somehow

* awaitable concat

* awaitable detect

* awaitable every/filter

* awaitable groupBy

* awaitable map/mapValues

* awaitable reduce

* awaitable reject

* awaitable some

* awaitable transform

* awaitable times

* awaitable auto

* awaitable compose/seq

* awaitable whilst/until (lol)

* awaitable forever

* awaitable parallel/race

* awaitable retry

* awaitable series (lol)

* awaitable tryEach

* awaitable waterfall (lol)

* lint

* cleanup, remove noop and unused internal functions

1 files changed, 7 insertions, 4 deletions

diff --git a/lib/reduce.js b/lib/reduce.js
index 1a6c036..571bc5a 100644
--- a/lib/reduce.js
+++ b/lib/reduce.js
@@ -1,7 +1,7 @@
 import eachOfSeries from './eachOfSeries';
-import noop from './internal/noop';
 import once from './internal/once';
 import wrapAsync from './internal/wrapAsync';
+import awaitify from './internal/awaitify'
 
 /**
  * Reduces `coll` into a single value using an async `iteratee` to return each
@@ -32,6 +32,7 @@ import wrapAsync from './internal/wrapAsync';
  * @param {Function} [callback] - A callback which is called after all the
  * `iteratee` functions have finished. Result is the reduced value. Invoked with
  * (err, result).
+ * @returns {Promise} a promise, if no callback is passed
  * @example
  *
  * async.reduce([1,2,3], 0, function(memo, item, callback) {
@@ -43,13 +44,15 @@ import wrapAsync from './internal/wrapAsync';
  *     // result is now equal to the last value of memo, which is 6
  * });
  */
-export default function reduce(coll, memo, iteratee, callback) {
-    callback = once(callback || noop);
+function reduce(coll, memo, iteratee, callback) {
+    callback = once(callback);
     var _iteratee = wrapAsync(iteratee);
-    eachOfSeries(coll, (x, i, iterCb) => {
+    return eachOfSeries(coll, (x, i, iterCb) => {
         _iteratee(memo, x, (err, v) => {
             memo = v;
             iterCb(err);
         });
     }, err => callback(err, memo));
 }
+export default awaitify(reduce, 4)
+