just-completion: "export def" -> "export extern"

[1adept]

Changing "export def" to "export extern" to not shadow the original command as it would disallow anything not defined in the re-definition

There seem to be similar cases in completions for (naive search with "rg 'export def'")

• mask
• winget (exports some defs and some externs. So i dont know if those defs are actually additional functionality)
• pnpm (only exports some 'nu-complete' defs)
• pass (only exports some 'nu-complete' defs)

I don't feel comfortable changing those as i am not familiar with them.

[kubouch]

extern do not support custom code block like def, it's only used to shadow an external. The fact that it accepts a block is a bug. See https://www.nushell.sh/book/externs.html how to use extern.

[1adept]

Sorry, if i wasn't clear. I am aware that def shadows the original definition. That is why i am making this pr.

I was questioning some of the other "export def" occurrences (especially in winget). To me it seemed like those should also use "extern" instead of "def" or shouldn't export their defs in the first place

[kubouch]

If you want to use extern, you should remove the block { ... }. As-is in this PR, it's not a valid Nushell syntax anymore (despite the lack of a syntax error, but that's a bug). Seems like the custom code is not necessary, so extern should be fine. If custom code is necessary, to make the signature permissive, you can use def --wrapped.

[1adept]

Sorry, i misunderstood. I didn't realize that blocks are not allowed for extern. It should be fine now.
I also added the missing flags while i was at it