feat(terminal): surface exit code via virttext + nvim_get_chan_info #37987

Problem:
When a terminal process exits, "[Process Exited]" text is added
to the buffer contents.

Solution:
- Return `exitcode` field from `nvim_get_chan_info`.
- Show it in the default 'statusline'.
- Show exitcode as virtual text in the terminal buffer.

runtime/lua/vim/_core/util.lua

@@ -81,4 +81,22 @@ function M.source_is_lua(bufnr, line1, line2)
   return lang_tree:lang() == 'lua'
 end
 
+--- Returns the exit code string for the current buffer, given:
+--- - Channel is attached to the current buffer
+--- - Current buffer is a terminal buffer
+---
+--- @return string
+function M.term_exitcode()
+  local chan_id = vim.bo.channel
+  if chan_id == 0 or vim.bo.buftype ~= 'terminal' then
+    return ''
+  end
+
+  local info = vim.api.nvim_get_chan_info(chan_id)
+  if info.exitcode and info.exitcode >= 0 then
+    return string.format('[Exit: %d]', info.exitcode)
+  end
+  return ''
+end
+
 return M

runtime/lua/vim/_meta/api.lua

@@ -1309,6 +1309,7 @@ function vim.api.nvim_get_autocmds(opts) end
 --- -  "buffer"  (optional) Buffer connected to |terminal| instance.
 --- -  "client"  (optional) Info about the peer (client on the other end of the channel), as set
 ---              by |nvim_set_client_info()|.
+--- - "exitcode" (optional) Exit code of the |terminal| process.
 ---
 function vim.api.nvim_get_chan_info(chan) end
 

runtime/lua/vim/_meta/options.lua

@@ -6964,7 +6964,7 @@ vim.wo.stc = vim.wo.statuscolumn
 ---
 ---
 --- @type string
-vim.o.statusline = "%<%f %h%w%m%r %=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &busy > 0 ? '◐ ' : '' %}%{% luaeval('(package.loaded[''vim.diagnostic''] and #vim.diagnostic.count() ~= 0 and vim.diagnostic.status() .. '' '') or '''' ') %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
+vim.o.statusline = "%<%f %h%w%m%r %{% v:lua.require('vim._core.util').term_exitcode() %}%=%{% &showcmdloc == 'statusline' ? '%-10.S ' : '' %}%{% exists('b:keymap_name') ? '<'..b:keymap_name..'> ' : '' %}%{% &busy > 0 ? '◐ ' : '' %}%{% luaeval('(package.loaded[''vim.diagnostic''] and #vim.diagnostic.count() ~= 0 and vim.diagnostic.status() .. '' '') or '''' ') %}%{% &ruler ? ( &rulerformat == '' ? '%-14.(%l,%c%V%) %P' : &rulerformat ) : '' %}"
 vim.o.stl = vim.o.statusline
 vim.wo.statusline = vim.o.statusline
 vim.wo.stl = vim.wo.statusline