Subject: [PATCH]: Eglot, request progress notification on server init

From: Danny Freeman <[email-masked]>
Date: Fri, 09 Dec 2022 14:55:05 -0500

I would like to propose a change to Eglot that builds on my last patch
in bug 59149.

What I did not realize at the time of writing that patch, is that
clients can opt into receiving progress notifications for server
initialization when sending the `:initialize` request.
This is useful for slow starting servers or large projects that require
the lsp server to do a lot of analysis on startup. The server of course
has to be able to send these progress reports. Not all of them do and
may ignore this parameter.

If users do not want to see this, they can set `eglot-report-progress`
to `nil`.

There are other requests that extend the WorkDoneProgressParams
interface that this could also be done for. It may be worth looking
through the spec and seeing if it makes sense to send this param with
other requests. Many of them are for typically quick requests like
`textDocument/definition`

Thank you,
-- 
Danny Freeman

>From 1b81fa34ff282bfca0f754afad2c9eca04ad7985 Mon Sep 17 00:00:00 2001
From: dannyfreeman <[email-masked]>
Date: Fri, 9 Dec 2022 14:40:01 -0500
Subject: [PATCH] Eglot: show progress reports for slow starting servers

* lisp/progmodes/eglot.el (eglot--connect): report progress on
initialization

This takes advantage of the new `eglot-handle-notification`
implementation of the LSP $/progress method.

Slow starting servers will now show their progress in the
minibuffer if `eglot-report-progress` is `t`. The server must
also opt in to providing the $/progress notifications.

See
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize
for more information on the InitializeParams interface.
---
 lisp/progmodes/eglot.el | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el
index a53f62fc565..cceb9fb5b32 100644
--- a/lisp/progmodes/eglot.el
+++ b/lisp/progmodes/eglot.el
@@ -1291,7 +1291,10 @@ eglot--connect
                             :initializationOptions (eglot-initialization-options
                                                     server)
                             :capabilities (eglot-client-capabilities server)
-                            :workspaceFolders (eglot-workspace-folders server))
+                            :workspaceFolders (eglot-workspace-folders server)
+                            ;; Request $/progress notifications from the
+                            ;; server on startup.
+                            :workDoneToken "initialize")
                       :success-fn
                       (eglot--lambda ((InitializeResult) capabilities serverInfo)
                         (unless canceled
-- 
2.38.1