use --ast-check in the fmt command

Author: g-w1

autoload/zig/fmt.vim

@@ -13,7 +13,7 @@ function! zig#fmt#Format() abort
     return
   endif
 
-  let cmdline = 'zig fmt --stdin'
+  let cmdline = 'zig fmt --stdin --ast-check'
   let current_buf = bufnr('')
 
   " The formatted code is output on stdout, the errors go on stderr.
@@ -22,8 +22,19 @@ function! zig#fmt#Format() abort
   else
     silent let out = split(system(cmdline, current_buf))
   endif
+  if len(out) == 1
+    if out[0] == "error: unrecognized parameter: '--ast-check'"
+      let cmdline = 'zig fmt --stdin'
+      if exists('*systemlist')
+        silent let out = systemlist(cmdline, current_buf)
+      else
+        silent let out = split(system(cmdline, current_buf))
+      endif
+    endif
+  endif
   let err = v:shell_error
 
+
   if err == 0
     " remove undo point caused via BufWritePre.
     try | silent undojoin | catch | endtry