I like to use class in JS to have types, some features are still missing in the major browsers like interfaces, some static stuff (I forgot), I miss the private

I like to use class in JS to have types, some features are still missing in the major browsers like interfaces, some static stuff (I forgot), I miss the private and protected keywords , my IDE can show me errors for using the wrong types or even from JSDoc documentation but JS needs a standalone compiler/checker that will detect type errors at "compile" time.