feat: format() takes an optional callback (#21)

* refactor: replicate lsp.buf.format call

* feat: format() takes an optional callback

* fix: improper logging

* fix: callback returns error if buffer is no longer valid

* fix: provide more detailed error message to callback

* fix: properly detect task interruption

* cleanup: remove unnecessary error code translation

* fix: lsp formatting for Neovim 0.9

* doc: add example of async formatting on save

* fix: async LSP formatter discards changes if buffer was modified

* fix: error code comparison

* fix: use the same LSP client filtering logic everywhere

* fix: add buffer validity guard checks

* fix: add buffer validity guard to LSP formatter

* refactor: change the default log level to WARN

1 files changed, 9 insertions, 3 deletions

diff --git a/lua/conform/log.lua b/lua/conform/log.lua
index 753a3c6..3e31fd2 100644
--- a/lua/conform/log.lua
+++ b/lua/conform/log.lua
@@ -5,7 +5,7 @@ vim.tbl_add_reverse_lookup(levels)
 local Log = {}
 
 ---@type integer
-Log.level = vim.log.levels.ERROR
+Log.level = vim.log.levels.WARN
 
 ---@return string
 Log.get_logfile = function()
@@ -33,11 +33,17 @@ local function format(level, msg, ...)
     end
   end
   local ok, text = pcall(string.format, msg, vim.F.unpack_len(args))
+  local timestr = vim.fn.strftime("%H:%M:%S")
   if ok then
     local str_level = levels[level]
-    return string.format("%s[%s] %s", vim.fn.strftime("%H:%M:%S"), str_level, text)
+    return string.format("%s[%s] %s", timestr, str_level, text)
   else
-    return string.format("[ERROR] error formatting log line: '%s' args %s", msg, vim.inspect(args))
+    return string.format(
+      "%s[ERROR] error formatting log line: '%s' args %s",
+      timestr,
+      vim.inspect(msg),
+      vim.inspect(args)
+    )
   end
 end