Proxy and Reflect
Widely available since 2019-03-20
The Proxy and Reflect JavaScript built-ins intercept and define custom behavior for fundamental language operations (such as property lookup, assignment, enumeration, or function invocation).
Learning resources on MDN
Browser support (view on caniuse.com)
- Chrome 49 Released on 2016-03-02
- Chrome Android 49 Released on 2016-03-09
- Edge 12 Released on 2015-07-29
- Firefox 18 Released on 2013-01-08
- Firefox for Android 18 Released on 2013-01-08
- Safari 10 Released on 2016-09-20
- Safari on iOS 10 Released on 2016-09-13
Specifications
- ECMAScript Language Specification (#sec-reflection), from TC39 (Ecma International).