fix: multi filetype config chaining (#214)

* fix: multi filetype config chaining

* chore(doc): auto generate docs

* ci: add more tests for filetypes

* chore: fix type warning

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: xiaoshihou514

doc/guard.nvim.txt

@@ -1,4 +1,4 @@
-*guard.nvim.txt*           For NVIM v0.8.0           Last change: 2025 June 08
+*guard.nvim.txt*           For NVIM v0.8.0           Last change: 2025 June 10
 
 ==============================================================================
 Table of Contents                               *guard.nvim-table-of-contents*

lua/guard/filetype.lua

@@ -70,7 +70,9 @@ local function box(ft)
     local events = require('guard.events')
     for _, it in ipairs(self:ft()) do
       if it ~= ft then
-        M[it] = box(it)
+        if not getmetatable(M[it]) then
+          M[it] = box(it)
+        end
         M[it].formatter = self.formatter
       end
 
@@ -82,10 +84,6 @@ local function box(ft)
         events.fmt_attach_to_existing(it)
       end
     end
-
-    if ft:find(',') then
-      M[ft] = nil
-    end
     return self
   end
 
@@ -101,7 +99,10 @@ local function box(ft)
     local evs = util.linter_events(config)
     for _, it in ipairs(self:ft()) do
       if it ~= ft then
-        M[it] = box(it)
+        if not getmetatable(M[it]) then
+          M[it] = box(it)
+          vim.print('init ' .. it)
+        end
         M[it].linter = self.linter
       end
 

lua/guard/health.lua

@@ -18,7 +18,12 @@ end
 
 local function executable_check()
   local checked = {}
-  for _, item in pairs(filetype) do
+  for ft, item in pairs(filetype) do
+    if ft:find(',') then
+      goto continue
+    end
+
+    -- run executable or custom healt check
     for _, conf in ipairs(item.formatter or {}) do
       if conf.health then
         conf.health()
@@ -33,6 +38,8 @@ local function executable_check()
         check_cmd(conf, checked)
       end
     end
+
+    ::continue::
   end
   if pcall(require, 'mason') then
     health.warn(

lua/guard/util.lua

@@ -140,7 +140,7 @@ end
 function M.buf_get_info(buf)
   local fname = vim.fn.fnameescape(resolve_symlink(api.nvim_buf_get_name(buf)))
   ---@diagnostic disable-next-line: undefined-field
-  return fname, M.get_lsp_root() or vim.uv.cwd()
+  return fname, assert(M.get_lsp_root() or vim.uv.cwd())
 end
 
 ---@param c (FmtConfig|LintConfig)?

spec/filetype_spec.lua

@@ -100,6 +100,29 @@ describe('filetype module', function()
     }, ft.javascriptreact)
   end)
 
+  it(
+    'can register a formatter for multiple filetypes simultaneously while chaining configs',
+    function()
+      ft('javascript,javascriptreact')
+        :fmt({
+          cmd = 'cat',
+          args = { '-v', '-E' },
+        })
+        :append({ cmd = 'tac' })
+        :lint({ cmd = 'cat' })
+        :append({ cmd = 'tac' })
+
+      same({
+        formatter = { { cmd = 'cat', args = { '-v', '-E' } }, { cmd = 'tac' } },
+        linter = { { cmd = 'cat' }, { cmd = 'tac' } },
+      }, ft.javascript)
+      same({
+        formatter = { { cmd = 'cat', args = { '-v', '-E' } }, { cmd = 'tac' } },
+        linter = { { cmd = 'cat' }, { cmd = 'tac' } },
+      }, ft.javascriptreact)
+    end
+  )
+
   it('can add extra command arguments', function()
     ft('c')
       :fmt({