Coming to the spec soonish and already supported in Babel - <a href="https:&#x2F;&#x2F;github.com&#x2F;jeffmo&#x2F;es-class-fields-and-static-properties" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;jeffmo&#x2F;es-class-fields-and-static-propert...</a>