I am using spread operator in redux for react-native in mobile app development.
Is there any possibility that spread operator would not work for some older device that supported by react-native? Not sure how react-native work underlying (does the native app created by react-native depend on underlying browser that support es6??)

What about in react? Assuming that react support that browser version but the browser itself does not support es6 syntax. Would the spread operator in redux be working?

I am thinking should I be using spread operator as I am not sure whether the spread operator is handled by react/react-native or by the browser.

I would want to use spread operator but I do not want:   

1) For react-native mobile app, at the end of the day it will not pass QA testing on android 4.4.  

2) For react js, at the end of the day it will not work on a browser that it is supported by react js but does not have es6 compatibility.  

So my question is does react/react-native handle the spread operator or any es6 function internally or it would be depend on external browser/plugin?

**Note:**
I am talking about .js file not .jsx file in react-native.