[nilliams]

I don't think many have embraced the .jsx extension.

And arguably it doesn't make a lot of sense, because when working with most modern frameworks/libs, JSX is not the only non-standard-js element in the file. Should we call it .es6, .es2015, .es2015+jsx ?

So yeah, sticking with .js is common.

[TazeTSchnitzel]

ES2015 is standard JS. Maybe not widely deployed, but it's standard.

JSX is not.