feat(lsp): add lsp healthcheck

Add healthcheck for language server client, currently only checks
logging status.

runtime/autoload/health/lsp.vim

@@ -0,0 +1,5 @@
+function! health#lsp#check() abort
+  call health#report_start('Checking language server client configuration')
+  lua require 'vim.lsp.health'.check_health()
+endfunction
+

runtime/lua/vim/lsp/health.lua

@@ -0,0 +1,27 @@
+local M = {}
+
+--- Performs a healthcheck for LSP
+function M.check_health()
+  local report_info = vim.fn['health#report_info']
+  local report_warn = vim.fn['health#report_warn']
+
+  local log = require('vim.lsp.log')
+  local current_log_level = log.get_level()
+  local log_level_string = log.levels[current_log_level]
+  report_info(string.format("LSP log level : %s", log_level_string))
+
+  if current_log_level < log.levels.WARN then
+    report_warn(string.format("Log level %s will cause degraded performance and high disk usage", log_level_string))
+  end
+
+  local log_path = vim.lsp.get_log_path()
+  report_info(string.format("Log path: %s", log_path))
+
+  local log_size = vim.loop.fs_stat(log_path).size
+
+  local report_fn = (log_size / 1000000 > 100 and report_warn or report_info)
+  report_fn(string.format("Log size: %d KB", log_size / 1000 ))
+end
+
+return M
+

runtime/lua/vim/lsp/log.lua

@@ -88,6 +88,11 @@ function log.set_level(level)
   end
 end
 
+--- Gets the current log level.
+function log.get_level()
+  return current_log_level
+end
+
 --- Checks whether the level is sufficient for logging.
 ---@param level number log level
 ---@returns (bool) true if would log, false if not