Yeah I mean, many compile-to-JS languages have pretty good ecosystems (I know Elm is one, and I believe you that ClojureScript is too), but it's always going to be a pain in the ass at some point. Hell, I've been wrestling with just setting up Jest with TypeScript not that long ago, and measuring code coverage still isn't perfect. You're not going to tell me that you never run into those sort of things with non-JS languages that compile to JS.