It's a really good idea and one my company implemented on top of Kotlin Scripting as well. There's a lot of scope for competitors to bash. It's not really a public product (and not open source), but a while ago I uploaded a version and docsite to show some friends:
https://hshell.hydraulic.dev/13.0/
I'm not sure what to do with it, maintaining open source projects can be a lot of work but I doubt there's much of a market for such a tool. Still, Hshell has some neat features I hope to see in other bash competitors:
• Fully battle tested on Windows. The core code is the same as in Conveyor, a commercial product. The APIs abstract Win/UNIX differences like xattrs, permission bits, path delimiters, built in commands etc. The blog post talks about Windows but iirc Bun itself doesn't really work there yet.
• Fairly extensive shell API with commands like mv, cp, wget, find, hash and so on. The semantics deviate from POSIX in some places for convenience, for example, commands are recursive by default so there's no need for a separate "rm -rf" type command. Regular rm will do the right thing when applied to a directory. You can also do things like `sha256("directory")` and it'll recursively hash the directory contents. Operations execute in parallel by default which is a big win on SSDs.
• Run commands like this:
val result = "foo --bar"()
Running commands has some nice features: you can redirect output to both files, the log and lambda functions, and the type of "result" is flexible. Declare it as List and you get a list of lines, declare it as String and the stdout is all in one.
• Built in progress tracking for all long running operations, complete with a nice animated pulsing Unicode progress bar. You can also track sub-tasks and those get an equally nice rendering (see the Conveyor demo video for an example). There are extensions to collections and streams that let you iterate over them with automatic progress tracking.
• You can ssh to a remote machine and the shell API continues to work. Executing commands runs them remotely. If you use the built-in wget command it will run that download remotely too, but with progress callbacks and other settings propagated from the local script.
• You can define high quality CLIs by annotating top level variables. There are path/directory assertions that show spelling suggestions if they're not found.
• Can easily import any dependency from Maven Central.
And so on. We use it for all our scripting needs internally now and it's a real delight.
Compared to Bun Scripting there are a few downsides:
1. The kotlin compiler is slow, so editing a script it incurs a delay of several seconds (running is fast). JS doesn't have that issue and Bun is especially fast to start. JetBrains are making it faster, and I want to experiment with compiling kotlinc to a native image at some point, but we never got around to it.
2. Bun's automatic shell escaping is really nice! I think we'd have to wait for the equivalent string interpolation feature to ship in Java and then be exposed to Kotlin. It's being worked on at the moment.
3. Obviously, Bun Scripting aims to be a product, whereas hshell is more an internal thing that we're not sure whether to try and grow a userbase for or not. So Bun is more practically useful today. For example the full API docs for hshell are still internal, only the general user guide is public.
4. Editing Kotlin scripts works best in IntelliJ and IntelliJ is an IDE more than an editor. It really wants files to be organized into projects, which doesn't fit the more ad hoc nature of shell scripts. It's a minor irritant, but real.
I think with some more work these problems can be fixed. For now, hopefully hshell's feature set inspires some other people!