Mozilla claimed it would remove __proto__ a while back (~2008) and it is still in the browser. Is it still going to be deprecated? It works in Opera, (Safari I think) and Ch
I think the actual point Mozilla wanted to make is that it's nonstandard, so the implementors would be perfectly within their rights removing it.
The cleaner way to do prototype chains is Object.create. The equivalent of your code, to create an object a with the prototype {'a': 'test'}, is:
a = Object.create({'a':'test'})
There are also shims to mimic this function in browsers that don't support it, if you ever need to work with one, which is another advantage over directly messing around with __proto__.