feat(config): P3 config batch — group 2 (create_link, dir_link, auto_header)

- create_link (default true): server resolve_target_uri now only synthesises a
  missing-page URI when create_link is set; when off, following a link to a
  non-existent page returns no location (no-op).
- dir_link: a [[dir/]] link now resolves to <dir>/<dir_link><ext> when dir_link
  is set, else opens the directory itself. Uses the already-parsed
  LinkTarget.is_directory.
- auto_header (default off): new wiki pages get a `= Stem =` header derived from
  the filename, skipping the wiki index + diary index. Client-side BufNewFile
  autocmd in both clients (init.lua + plugin/nuwiki.vim), with auto_header
  handlers in both command layers (trailing-slash-robust root matching).

Tests: cmd.auto_header_inserts + cmd.auto_header_skips_diary_index (nvim) /
cmd.auto_header_skips_index (vim). Full rust suite + both harnesses green
(Neovim 307, Vim 301/18/21).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

autoload/nuwiki/commands.vim

@@ -190,6 +190,30 @@ function! nuwiki#commands#auto_chdir() abort
   endif
 endfunction
 
+" vimwiki `auto_header`: on a new wiki page, insert a level-1 header derived
+" from the filename. Skips the wiki index + diary index pages; only acts on an
+" empty new buffer. Wired from a BufNewFile autocmd.
+function! nuwiki#commands#auto_header() abort
+  if line('$') > 1 || getline(1) !=# ''
+    return
+  endif
+  let l:file = expand('%:p')
+  for l:c in nuwiki#commands#wiki_list()
+    let l:root = fnamemodify(expand(l:c.root), ':p')
+    if l:root[len(l:root) - 1:] !=# '/' | let l:root .= '/' | endif
+    if l:file[: len(l:root) - 1] ==# l:root
+      let l:index_path = l:root . l:c.idx . l:c.ext
+      let l:diary_index_path = l:root . l:c.diary_rel . '/' . l:c.diary_idx . l:c.ext
+      if l:file ==# l:index_path || l:file ==# l:diary_index_path
+        return
+      endif
+      break
+    endif
+  endfor
+  call setline(1, '= ' . expand('%:t:r') . ' =')
+  call append(1, '')
+endfunction
+
 " :VimwikiShowVersion / :NuwikiShowVersion — echo the nuwiki version and the
 " host editor, mirroring upstream's version banner.
 function! nuwiki#commands#show_version() abort

crates/nuwiki-lsp/src/lib.rs

@@ -269,7 +269,29 @@ impl Backend {
                         }
                     }
                     let path = target.path.as_deref()?;
-                    return synthesise_page_uri(&source_wiki.config, path);
+                    // vimwiki `dir_link`: a `[[dir/]]` link opens `<dir>/<dir_link>`
+                    // (e.g. `index` → `dir/index.wiki`); empty → the directory itself.
+                    if target.is_directory {
+                        let dl = source_wiki.config.dir_link.trim();
+                        if dl.is_empty() {
+                            let mut p = source_wiki.config.root.clone();
+                            for seg in path.split('/').filter(|s| !s.is_empty()) {
+                                p.push(seg);
+                            }
+                            return Url::from_file_path(p).ok();
+                        }
+                        let joined = format!("{}/{dl}", path.trim_end_matches('/'));
+                        return synthesise_page_uri(&source_wiki.config, &joined);
+                    }
+                    // vimwiki `create_link`: when off, only follow to a page that
+                    // already exists on disk — never synthesise a new one.
+                    let uri = synthesise_page_uri(&source_wiki.config, path)?;
+                    if !source_wiki.config.create_link
+                        && !uri.to_file_path().map(|p| p.exists()).unwrap_or(false)
+                    {
+                        return None;
+                    }
+                    return Some(uri);
                 }
                 // No wiki registered (no `initializationOptions`, no
                 // workspace folder). Fall back to the source buffer's

development/tests/test-keymaps-vim.vim

@@ -728,6 +728,23 @@ endtry
 call s:record(s:nm_err ==# '' ? 1 : 0,
       \ 'cmd.VimwikiSearch_no_match_graceful', 'err=' . s:nm_err)
 
+" ===== auto_header inserts `= Stem =` on a new wiki page; skips the index =====
+let s:ah_root = fnamemodify(expand(nuwiki#commands#wiki_list()[0].root), ':p')
+if s:ah_root[len(s:ah_root)-1:] !=# '/' | let s:ah_root .= '/' | endif
+new
+execute 'file ' . fnameescape('/tmp/nuwiki-ah-plain/MyNewPage.wiki')
+call nuwiki#commands#auto_header()
+call s:record(getline(1) ==# '= MyNewPage =' ? 1 : 0,
+      \ 'cmd.auto_header_inserts', 'line1=' . getline(1))
+bwipeout!
+new
+execute 'file ' . fnameescape(s:ah_root . 'index.wiki')
+call nuwiki#commands#auto_header()
+call s:record(getline(1) ==# '' ? 1 : 0,
+      \ 'cmd.auto_header_skips_index', 'line1=' . getline(1))
+bwipeout!
+unlet s:ah_root
+
 " ===== :VimwikiGoto -nargs=* =====
 " Was -nargs=1, so a page name with a space raised E488 (and the empty-arg
 " prompt fallback was unreachable). Now -nargs=*: a multi-word arg must parse.

development/tests/test-keymaps.lua

@@ -305,6 +305,31 @@ vim.defer_fn(function()
     vim.cmd('bwipeout!')
   end
 
+  -- auto_header: the function inserts `= Stem =` on an empty new wiki buffer,
+  -- and skips the wiki index page. Operate on dedicated buffer handles so the
+  -- harness's own buffer is untouched.
+  do
+    local wroot = require('nuwiki.config').wiki_cfg(0).root
+    local root = vim.fn.fnamemodify(vim.fn.expand(wroot), ':p')
+    if root:sub(-1) ~= '/' then root = root .. '/' end
+    local function ah_line(name)
+      local buf = vim.api.nvim_create_buf(true, false)
+      vim.api.nvim_buf_set_name(buf, name)
+      require('nuwiki.commands').auto_header(buf)
+      local line = vim.api.nvim_buf_get_lines(buf, 0, 1, false)[1] or ''
+      vim.api.nvim_buf_delete(buf, { force = true })
+      return line
+    end
+    -- A normal page (outside any wiki root) → header inserted.
+    local got = ah_line('/tmp/nuwiki-ah-plain/MyNewPage.wiki')
+    record(got == '= MyNewPage =', 'cmd.auto_header_inserts', 'line1=' .. got)
+    -- The diary index page → skipped (no header). (The wiki index itself is the
+    -- harness's open buffer, so use the diary index to avoid an E95 collision.)
+    local c = require('nuwiki.config').wiki_cfg(0)
+    local idx_line = ah_line(root .. c.diary_rel .. '/' .. c.diary_idx .. '.wiki')
+    record(idx_line == '', 'cmd.auto_header_skips_diary_index', 'line1=' .. idx_line)
+  end
+
   -- ===== Lists =====
 
   run('list.toggle_via_C-Space', {

lua/nuwiki/commands.lua

@@ -285,6 +285,37 @@ function M.show_version()
   }, false, {})
 end
 
+-- vimwiki `auto_header`: on a new wiki page, insert a level-1 header derived
+-- from the filename. Skips the wiki index + diary index pages, and only acts
+-- on a genuinely empty buffer. Called from a BufNewFile autocmd.
+function M.auto_header(bufnr)
+  bufnr = bufnr or vim.api.nvim_get_current_buf()
+  local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+  if #lines > 1 or (lines[1] or '') ~= '' then
+    return -- not an empty new buffer
+  end
+  local file = vim.api.nvim_buf_get_name(bufnr)
+  local config = require('nuwiki.config')
+  for i = 0, 64 do
+    local c = config.wiki_cfg(i)
+    if not c then break end
+    local root = vim.fn.fnamemodify(vim.fn.expand(c.root), ':p')
+    if root:sub(-1) ~= '/' then root = root .. '/' end
+    if file:sub(1, #root) == root then
+      -- Skip the wiki index and the diary index pages.
+      local index_path = root .. c.idx .. c.ext
+      local diary_index_path = root .. c.diary_rel .. '/' .. c.diary_idx .. c.ext
+      if file == index_path or file == diary_index_path then
+        return
+      end
+      break
+    end
+    if not (config.options.wikis or vim.g.nuwiki_wikis) then break end
+  end
+  local title = vim.fn.fnamemodify(file, ':t:r')
+  vim.api.nvim_buf_set_lines(bufnr, 0, 1, false, { '= ' .. title .. ' =', '' })
+end
+
 -- :VimwikiSearch / :VWS {pattern} — search the current wiki's files (upstream
 -- scopes to the wiki, not the editor CWD). Resolves the wiki whose root holds
 -- the current file, else the first configured wiki, else CWD. Empty pattern

lua/nuwiki/init.lua

@@ -113,6 +113,22 @@ function M.setup(opts)
     vim.g.nuwiki_no_calendar = 1
   end
 
+  -- vimwiki `auto_header` (default off): insert a level-1 header from the
+  -- filename on new wiki pages. BufNewFile (not FileType) so it only fires for
+  -- genuinely new files.
+  if config.options.auto_header == true then
+    local ext = (config.options.file_extension or '.wiki'):gsub('^%.', '')
+    local pats = { '*.wiki' }
+    if ext ~= 'wiki' and ext ~= '' then
+      pats[#pats + 1] = '*.' .. ext
+    end
+    vim.api.nvim_create_autocmd('BufNewFile', {
+      pattern = pats,
+      group = vim.api.nvim_create_augroup('nuwiki_auto_header', { clear = true }),
+      callback = function(a) require('nuwiki.commands').auto_header(a.buf) end,
+    })
+  end
+
   lsp.register()
   _setup_global_mappings()
   _setup_global_commands()

plugin/nuwiki.vim

@@ -69,6 +69,19 @@ augroup nuwiki_vim_lsp_start
   autocmd FileType vimwiki call nuwiki#lsp#start()
 augroup END
 
+" vimwiki `auto_header` (default off): insert a level-1 header from the filename
+" on new wiki pages. BufNewFile fires only for genuinely new files. Matches the
+" configured extension(s).
+if get(g:, 'nuwiki_auto_header', 0)
+  let s:awh_ext = get(g:, 'nuwiki_file_extension', '.wiki')
+  let s:awh_ext = s:awh_ext[0] ==# '.' ? s:awh_ext : '.' . s:awh_ext
+  augroup nuwiki_auto_header
+    autocmd!
+    execute 'autocmd BufNewFile *' . s:awh_ext . ' call nuwiki#commands#auto_header()'
+  augroup END
+  unlet s:awh_ext
+endif
+
 " Global wiki-picker commands — available from any buffer so a wiki can be
 " chosen before a .wiki file exists. The picker reads its list from config
 " (no LSP); opening the chosen index then auto-starts the server. The