Corrected behavior of DexiePromise.finally():

If the onFinally callback returns a promise, wait for it before returning value. And if that promise rejects, return that rejection instead. This all according to spec. Earlier version did just call onFinally() and then return the original value - it did not allow for the onFinally to perform async work before continuing and it did not reject if the onFinally returned rejected promise or threw error.

src/helpers/promise.js

@@ -212,11 +212,9 @@ props(DexiePromise.prototype, {
 
     finally: function (onFinally) {
         return this.then(value => {
-            onFinally();
-            return value;
+            return DexiePromise.resolve(onFinally()).then(()=>value);
         }, err => {
-            onFinally();
-            return PromiseReject(err);
+            return DexiePromise.resolve(onFinally()).then(()=>PromiseReject(err));
         });
     },