`language plugin list` for bad plugin slugs should throw warning

[David Vielhuber]

Hello!

When I type

wp language plugin list foobar

I always get an output:

I can write anything I want:

This should not be the case :-)

[Janw Oostendorp]

A candidate for good-first-issue ?

Should return a nice error.

[Alain Schlesser]

Ah, it looks like this is a combination of the command not checking for the plugin's existence and WP Core always having a default language for anything.

I guess we should throw warnings for missing plugins and skip them, which would then end up with an empty list if no valid plugin slugs were provided.

[Mike Straw]

I'll take a look at this