implemented new promisify util

Author: Salakar

lib/utils/promisify.js

@@ -1,14 +1,14 @@
-export const promisify = (fn, NativeModule) => (...args) => {
-  return new Promise((resolve, reject) => {
-    const handler = (err, resp) => {
-      setTimeout(() => {
-        err ? reject(err) : resolve(resp);
-      }, 0);
-    }
-    args.push(handler);
-    (typeof fn === 'function' ? fn : NativeModule[fn])
-      .call(NativeModule, ...args);
+const handler = (resolve, reject, err, resp) => {
+  setImmediate(() => {
+    if (err) return reject(err);
+    return resolve(resp);
   });
 };
 
-export default promisify
+export default(fn, NativeModule) => (...args) => {
+  return new Promise((resolve, reject) => {
+    const _fn = typeof fn === 'function' ? fn : NativeModule[fn];
+    if (!_fn || typeof _fn !== 'function') return reject(new Error('Missing function for promisify.'));
+    return fn.apply(NativeModule, ...args, handler.bind(handler, resolve, reject));
+  });
+};