6 files changed, 18 insertions, 27 deletions
diff --git a/runtime/lua/vim/_defaults.lua b/runtime/lua/vim/_defaults.lua
index 4216a2acb7..d71116117e 100644
--- a/runtime/lua/vim/_defaults.lua
+++ b/runtime/lua/vim/_defaults.lua
@@ -224,7 +224,7 @@ do
     local function cmd(opts)
       local ok, err = pcall(vim.api.nvim_cmd, opts, {})
       if not ok then
-        vim.api.nvim_err_writeln(err:sub(#'Vim:' + 1))
+        vim.api.nvim_echo({ { err:sub(#'Vim:' + 1) } }, true, { err = true })
       end
     end
 
diff --git a/runtime/lua/vim/_editor.lua b/runtime/lua/vim/_editor.lua
index 44f17b3f85..66815a967e 100644
--- a/runtime/lua/vim/_editor.lua
+++ b/runtime/lua/vim/_editor.lua
@@ -58,6 +58,7 @@ vim._extra = {
 
 --- @private
 vim.log = {
+  --- @enum vim.log.levels
   levels = {
     TRACE = 0,
     DEBUG = 1,
@@ -620,13 +621,8 @@ end
 ---@param opts table|nil Optional parameters. Unused by default.
 ---@diagnostic disable-next-line: unused-local
 function vim.notify(msg, level, opts) -- luacheck: no unused args
-  if level == vim.log.levels.ERROR then
-    vim.api.nvim_err_writeln(msg)
-  elseif level == vim.log.levels.WARN then
-    vim.api.nvim_echo({ { msg, 'WarningMsg' } }, true, {})
-  else
-    vim.api.nvim_echo({ { msg } }, true, {})
-  end
+  local chunks = { { msg, level == vim.log.levels.WARN and 'WarningMsg' or nil } }
+  vim.api.nvim_echo(chunks, true, { err = level == vim.log.levels.ERROR })
 end
 
 do
diff --git a/runtime/lua/vim/_meta/api.lua b/runtime/lua/vim/_meta/api.lua
index 7297c8ad38..f6d8153c27 100644
--- a/runtime/lua/vim/_meta/api.lua
+++ b/runtime/lua/vim/_meta/api.lua
@@ -1104,22 +1104,19 @@ function vim.api.nvim_del_var(name) end
 --- `hl_group` element can be omitted for no highlight.
 --- @param history boolean if true, add to `message-history`.
 --- @param opts vim.api.keyset.echo_opts Optional parameters.
+--- - err: Treat the message like `:echoerr`. Omitted `hlgroup`
+---   uses `hl-ErrorMsg` instead.
 --- - verbose: Message is printed as a result of 'verbose' option.
 ---   If Nvim was invoked with -V3log_file, the message will be
 ---   redirected to the log_file and suppressed from direct output.
 function vim.api.nvim_echo(chunks, history, opts) end
 
---- Writes a message to the Vim error buffer. Does not append "\n", the
---- message is buffered (won't display) until a linefeed is written.
----
---- @param str string Message
+--- @deprecated
+--- @param str string
 function vim.api.nvim_err_write(str) end
 
---- Writes a message to the Vim error buffer. Appends "\n", so the buffer is
---- flushed (and displayed).
----
---- @see vim.api.nvim_err_write
---- @param str string Message
+--- @deprecated
+--- @param str string
 function vim.api.nvim_err_writeln(str) end
 
 --- Evaluates a Vimscript `expression`. Dicts and Lists are recursively expanded.
@@ -1859,10 +1856,8 @@ function vim.api.nvim_open_term(buffer, opts) end
 --- @return integer # Window handle, or 0 on error
 function vim.api.nvim_open_win(buffer, enter, config) end
 
---- Writes a message to the Vim output buffer. Does not append "\n", the
---- message is buffered (won't display) until a linefeed is written.
----
---- @param str string Message
+--- @deprecated
+--- @param str string
 function vim.api.nvim_out_write(str) end
 
 --- Parse command line.
diff --git a/runtime/lua/vim/_meta/api_keysets.lua b/runtime/lua/vim/_meta/api_keysets.lua
index c08ab0663b..98e916115e 100644
--- a/runtime/lua/vim/_meta/api_keysets.lua
+++ b/runtime/lua/vim/_meta/api_keysets.lua
@@ -88,6 +88,7 @@ error('Cannot require a meta file')
 --- @field pattern? string|string[]
 
 --- @class vim.api.keyset.echo_opts
+--- @field err? boolean
 --- @field verbose? boolean
 
 --- @class vim.api.keyset.empty
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index 5d11312c77..a99363d3d6 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -702,14 +702,14 @@ local wait_result_reason = { [-1] = 'timeout', [-2] = 'interrupted', [-3] = 'err
 ---
 --- @param ... string List to write to the buffer
 local function err_message(...)
-  local message = table.concat(vim.iter({ ... }):flatten():totable())
+  local chunks = { { table.concat({ ... }) } }
   if vim.in_fast_event() then
     vim.schedule(function()
-      api.nvim_err_writeln(message)
+      vim.api.nvim_echo(chunks, true, { err = true })
       api.nvim_command('redraw')
     end)
   else
-    api.nvim_err_writeln(message)
+    vim.api.nvim_echo(chunks, true, { err = true })
     api.nvim_command('redraw')
   end
 end
diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index 1945040bda..3779c342e8 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -582,9 +582,8 @@ NSC['window/showMessage'] = function(_, params, ctx)
   if message_type == protocol.MessageType.Error then
     err_message('LSP[', client_name, '] ', message)
   else
-    --- @type string
-    local message_type_name = protocol.MessageType[message_type]
-    api.nvim_out_write(string.format('LSP[%s][%s] %s\n', client_name, message_type_name, message))
+    message = ('LSP[%s][%s] %s\n'):format(client_name, protocol.MessageType[message_type], message)
+    api.nvim_echo({ { message } }, true, { err = true })
   end
   return params
 end