Using ES 6 or parts of it?

[nrenner]

We currently don't use ES 6.

My idea was to either wait until we use Babel (with Webpack?) or to properly define what Browsers we want/need to support and what features we can safely use, ideally by looking at user agent strings from user requests.

The first thing would be to check the code with eslint-plugin-compat (#188) against our current browserlist (which is Browsers supporting flexbox):

brouter-web/package.json

Line 25 in 029bdad

"browserslist": "> 0.5%, last 2 versions, Firefox ESR, not dead, Explorer >= 10, Android >= 4.1, Safari >= 7, iOS >= 7",