feat: show deprecate servers list in LspInfo (#3308)

* feat: show deprecate servers list in LspInfo

In order to smoothly transition to the vim.lsp.start interface in the future,
adding checkhealth here is meaningless. Only the lspinfo information window
is available. So shown deprecate servers list in LspInfo and update the
server deprecate remove version to 0.2.1. 0.2.0 is tagged too
quickly cause some servers not removed.


Co-authored-by: Justin M. Keyes <justinkz@gmail.com>

3 files changed, 49 insertions, 29 deletions

diff --git a/doc/lspconfig.txt b/doc/lspconfig.txt
index ef5c1803..318e0622 100644
--- a/doc/lspconfig.txt
+++ b/doc/lspconfig.txt
@@ -461,7 +461,8 @@ COMMANDS                                                    *lspconfig-commands*
 
 - `:LspInfo` shows the status of active and configured language servers. Note
   that client id refers to the Nvim RPC instance connected to a given
-  language server.
+  language server. Also shows a list of deprecated servers that have been
+  configured.
 
 The following commands support tab-completion for all arguments. All commands
 that require a client id can either leverage tab-completion or the info
diff --git a/lua/lspconfig.lua b/lua/lspconfig.lua
index b9012f87..f5129bc6 100644
--- a/lua/lspconfig.lua
+++ b/lua/lspconfig.lua
@@ -4,44 +4,57 @@ local M = {
   util = require 'lspconfig.util',
 }
 
+--- Deprecated config names.
+---
 ---@class Alias
 ---@field to string The new name of the server
 ---@field version string The version that the alias will be removed in
----@param name string
----@return Alias
-local function server_alias(name)
-  local aliases = {
-    ['fennel-ls'] = {
-      to = 'fennel_ls',
-      version = '0.2.0',
-    },
-    ruby_ls = {
-      to = 'ruby_lsp',
-      version = '0.2.0',
-    },
-    ['starlark-rust'] = {
-      to = 'starlark_rust',
-      version = '0.2.0',
-    },
-    sumneko_lua = {
-      to = 'lua_ls',
-      version = '0.2.0',
-    },
-    tsserver = {
-      to = 'ts_ls',
-      version = '0.2.0',
-    },
-  }
+---@field inconfig? boolean need shown in lspinfo
+local aliases = {
+  ['fennel-ls'] = {
+    to = 'fennel_ls',
+    version = '0.2.1',
+  },
+  ruby_ls = {
+    to = 'ruby_lsp',
+    version = '0.2.1',
+  },
+  ['starlark-rust'] = {
+    to = 'starlark_rust',
+    version = '0.2.1',
+  },
+  sumneko_lua = {
+    to = 'lua_ls',
+    version = '0.2.1',
+  },
+  tsserver = {
+    to = 'ts_ls',
+    version = '0.2.1',
+  },
+}
 
-  return aliases[name]
+---@return Alias
+---@param name string|nil get this alias, or nil to get all aliases that were used in the current session.
+M.server_aliases = function(name)
+  if name then
+    return aliases[name]
+  end
+  local used_aliases = {}
+  for sname, alias in pairs(aliases) do
+    if alias.inconfig then
+      used_aliases[sname] = alias
+    end
+  end
+  return used_aliases
 end
 
 local mt = {}
 function mt:__index(k)
   if configs[k] == nil then
-    local alias = server_alias(k)
+    local alias = M.server_aliases(k)
     if alias then
       vim.deprecate(k, alias.to, alias.version, 'lspconfig', false)
+      alias.inconfig = true
       k = alias.to
     end
 
diff --git a/lua/lspconfig/ui/lspinfo.lua b/lua/lspconfig/ui/lspinfo.lua
index 886014aa..e0b9bf96 100644
--- a/lua/lspconfig/ui/lspinfo.lua
+++ b/lua/lspconfig/ui/lspinfo.lua
@@ -268,8 +268,14 @@ return function()
     '',
     'Configured servers list: ' .. table.concat(util.available_servers(), ', '),
   }
-
+  local deprecated_servers = {}
   vim.list_extend(buf_lines, matching_config_header)
+  for server_name, deprecate in pairs(require('lspconfig').server_aliases()) do
+    table.insert(deprecated_servers, ('%s -> %s'):format(server_name, deprecate.to))
+  end
+  if #deprecated_servers > 0 then
+    vim.list_extend(buf_lines, { '', 'Deprecated servers: ' .. table.concat(deprecated_servers, ' ') })
+  end
 
   local fmt_buf_lines = indent_lines(buf_lines, ' ')