--- /dev/null
+'use strict';
+module.exports = (promise, onFinally) => {
+ onFinally = onFinally || (() => {});
+
+ return promise.then(
+ val => new Promise(resolve => {
+ resolve(onFinally());
+ }).then(() => val),
+ err => new Promise(resolve => {
+ resolve(onFinally());
+ }).then(() => {
+ throw err;
+ })
+ );
+};