feat(lsp): show server version in `:checkhealth` #31611

Problem:
Language server version information missing from `:checkhealth vim.lsp`.

Solution:
Store `InitializeResult.serverInfo.version` from the `initialize`
response and display for each client in `:checkhealth vim.lsp`.

4 files changed, 13 insertions, 0 deletions

diff --git a/runtime/doc/lsp.txt b/runtime/doc/lsp.txt
index 83d191ed48..228bbafdd2 100644
--- a/runtime/doc/lsp.txt
+++ b/runtime/doc/lsp.txt
@@ -1126,6 +1126,9 @@ Lua module: vim.lsp.client                                        *lsp-client*
       • {server_capabilities}   (`lsp.ServerCapabilities?`) Response from the
                                 server sent on `initialize` describing the
                                 server's capabilities.
+      • {server_info}           (`lsp.ServerInfo?`) Response from the server
+                                sent on `initialize` describing information
+                                about the server.
       • {progress}              (`vim.lsp.Client.Progress`) A ring buffer
                                 (|vim.ringbuf()|) containing progress messages
                                 sent by the server. See
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 73704a143c..172fa4625c 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -115,6 +115,7 @@ LSP
 • |vim.lsp.util.make_position_params()|, |vim.lsp.util.make_range_params()|
   and |vim.lsp.util.make_given_range_params()| now require the `position_encoding`
   parameter.
+• `:checkhealth vim.lsp` displays the server version (if available).
 
 LUA
 
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index 72043c18dd..d51a45b473 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -174,6 +174,10 @@ local validate = vim.validate
 --- capabilities.
 --- @field server_capabilities lsp.ServerCapabilities?
 ---
+--- Response from the server sent on `initialize` describing information about
+--- the server.
+--- @field server_info lsp.ServerInfo?
+---
 --- A ring buffer (|vim.ringbuf()|) containing progress messages
 --- sent by the server.
 --- @field progress vim.lsp.Client.Progress
@@ -556,6 +560,8 @@ function Client:initialize()
       self.offset_encoding = self.server_capabilities.positionEncoding
     end
 
+    self.server_info = result.serverInfo
+
     if next(self.settings) then
       self:notify(ms.workspace_didChangeConfiguration, { settings = self.settings })
     end
diff --git a/runtime/lua/vim/lsp/health.lua b/runtime/lua/vim/lsp/health.lua
index d2cf888d89..d94bc70a65 100644
--- a/runtime/lua/vim/lsp/health.lua
+++ b/runtime/lua/vim/lsp/health.lua
@@ -40,6 +40,8 @@ local function check_active_clients()
   local clients = vim.lsp.get_clients()
   if next(clients) then
     for _, client in pairs(clients) do
+      local server_version = vim.tbl_get(client, 'server_info', 'version')
+        or '? (no serverInfo.version response)'
       local cmd ---@type string
       local ccmd = client.config.cmd
       if type(ccmd) == 'table' then
@@ -62,6 +64,7 @@ local function check_active_clients()
       end
       report_info(table.concat({
         string.format('%s (id: %d)', client.name, client.id),
+        string.format('- Version: %s', server_version),
         dirs_info,
         string.format('- Command: %s', cmd),
         string.format('- Settings: %s', vim.inspect(client.settings, { newline = '\n  ' })),