Such things are so subjective, but the sources I read usually only list the first three. I'm not opposed to learning about ClojureScript, but I have to make choices about where to spend my time. At this point, I think I need to focus on addressing JS Linters and what I think an answer would look like. When I write those up, I'd love to hear feedback from someone who knows ClojureScript about how closely (or not) it matches what I would be looking for.
TypeScript CoffeeScript Dart ClojureScript
you got 3 out of the 4 so far