Hi Paul,

I'm the author of Eglot, an LSP client for Emacs whose functionality will
soon (ish) be in Emacs itself. It explores a subset of the LSP protocol and
leverages it in terms of Emacs functions. You can use Eglot it to gauge how
developed a server is. You can -- and emacs-devel is the place to do that
-- extend Eglot to explore more of the LSP protocol, provided that the LSP
server you're using works in those regions unexplored by Eglot.  Not sure
if this is what you're looking for.

If you're strictly looking for a list of capabilities offered by the LSP
server in question, there is a section in the protocol specification
devoted to describing a protocol message with that information. That
protocol message is sent early on in the handshake, and you can easily
inspect it with the Eglot client (or other clients). Using Emacs or other
clients for this specific purpose would be mostly "indifferent" in your
categorization.

João

On Sun, Jul 26, 2020, 16:51 Paul Michael Reilly <pmr@pajato.com> wrote:

> I am looking for an LSP expert who can tell me if the notion of using
> Emacs to learn what kinds of capabilities a particular LSP server (Kotlin)
> provides is a good, bad or indifferent idea. Seems like someone here might
> be such a person.
>
> -pmr
>