Is there any dcl formatter? intellij default one formats the code really bad

Use EditorConfig to set up formatting that suits you and IJ will adhere

Is there some official one to just copy and use?

Effectively it is Kotlin, isn't it? So I'd expect the official Kotlin style to be the default one. 🤷‍♂️

I tried ktfmt but I had to do a workaround by changing the files to kts, format them with ktfmt, and change them again to dcl.

Well, open an issue with them. It should also support polyglot scripts that are Kotlin scripts and Bash scripts at the same time and similar which then often also is not named kts.

A formatter/linter is indeed planned. Please open an issue if you want to be notified when we'll get there.

I have seen ktfmt is being migrated as official formatter, I guess it will be the default one that would format dcl too, right?

Unsure at this stage