awaitable waterfall (lol)

2 files changed, 17 insertions, 3 deletions

diff --git a/lib/waterfall.js b/lib/waterfall.js
index f4c3ddc..f9a6c24 100644
--- a/lib/waterfall.js
+++ b/lib/waterfall.js
@@ -1,8 +1,8 @@
-import noop from './internal/noop';
 import once from './internal/once';
 
 import onlyOnce from './internal/onlyOnce';
 import wrapAsync from './internal/wrapAsync';
+import awaitify from './internal/awaitify'
 
 /**
  * Runs the `tasks` array of functions in series, each passing their results to
@@ -61,8 +61,8 @@ import wrapAsync from './internal/wrapAsync';
  *     callback(null, 'done');
  * }
  */
-export default  function(tasks, callback) {
-    callback = once(callback || noop);
+function waterfall (tasks, callback) {
+    callback = once(callback);
     if (!Array.isArray(tasks)) return callback(new Error('First argument to waterfall must be an array of functions'));
     if (!tasks.length) return callback();
     var taskIndex = 0;
@@ -82,3 +82,5 @@ export default  function(tasks, callback) {
 
     nextTask([]);
 }
+
+export default awaitify(waterfall)
diff --git a/test/es2017/awaitableFunctions.js b/test/es2017/awaitableFunctions.js
index b0b3bda..e226187 100644
--- a/test/es2017/awaitableFunctions.js
+++ b/test/es2017/awaitableFunctions.js
@@ -558,4 +558,16 @@ module.exports = function () {
         ], 2)
         expect(calls).to.eql([1, 2, 3])
     });
+
+    it('should return a Promise: waterfall', async () => {
+        expect (async.waterfall.name).to.contain('waterfall')
+        const calls = []
+        await async.waterfall([
+            async () => { await Promise.resolve(); calls.push(1) },
+            async () => { await Promise.resolve(); calls.push(2) },
+            async () => { await Promise.resolve(); calls.push(3) },
+            async () => { await Promise.resolve(); calls.push(4) },
+        ], 2)
+        expect(calls).to.eql([1, 2, 3, 4])
+    });
 };