feat: support unnamed buffer with single_file_support (#2226)

* feat: support unnamed buffer with single_file_support

* fix: make some code simple clear

* feat: update doc

* fix: grammar

* fix: grammar

2 files changed, 16 insertions, 11 deletions

diff --git a/lua/lspconfig/configs.lua b/lua/lspconfig/configs.lua
index 512c76b3..76586b5e 100644
--- a/lua/lspconfig/configs.lua
+++ b/lua/lspconfig/configs.lua
@@ -1,5 +1,5 @@
 local util = require 'lspconfig.util'
-local api, validate, lsp = vim.api, vim.validate, vim.lsp
+local api, validate, lsp, uv, fn = vim.api, vim.validate, vim.lsp, vim.loop, vim.fn
 local tbl_deep_extend = vim.tbl_deep_extend
 
 local configs = {}
@@ -90,15 +90,19 @@ function configs.__newindex(t, config_name, config_def)
       if get_root_dir then
         local bufnr = api.nvim_get_current_buf()
         local bufname = api.nvim_buf_get_name(bufnr)
-        if not util.bufname_valid(bufname) then
+        if #bufname == 0 and not config.single_file_support then
           return
+        elseif #bufname ~= 0 then
+          if not util.bufname_valid(bufname) then
+            return
+          end
+          root_dir = get_root_dir(util.path.sanitize(bufname), bufnr)
         end
-        root_dir = get_root_dir(util.path.sanitize(bufname), bufnr)
       end
 
       if root_dir then
         api.nvim_create_autocmd('BufReadPost', {
-          pattern = vim.fn.fnameescape(root_dir) .. '/*',
+          pattern = fn.fnameescape(root_dir) .. '/*',
           callback = function()
             M.manager.try_add_wrapper()
           end,
@@ -124,10 +128,10 @@ function configs.__newindex(t, config_name, config_def)
         -- this to attach additional files in the same parent folder to the same server.
         -- We just no longer send rootDirectory or workspaceFolders during initialization.
         local bufname = api.nvim_buf_get_name(0)
-        if not util.bufname_valid(bufname) then
+        if #bufname ~= 0 and not util.bufname_valid(bufname) then
           return
         end
-        local pseudo_root = util.path.dirname(util.path.sanitize(bufname))
+        local pseudo_root = #bufname == 0 and uv.cwd() or util.path.dirname(util.path.sanitize(bufname))
         local client_id = M.manager.add(pseudo_root, true)
         lsp.buf_attach_client(api.nvim_get_current_buf(), client_id)
       end
@@ -235,8 +239,12 @@ function configs.__newindex(t, config_name, config_def)
       local root_dir
 
       local bufname = api.nvim_buf_get_name(bufnr)
-      if not util.bufname_valid(bufname) then
+      if #bufname == 0 and not config.single_file_support then
         return
+      elseif #bufname ~= 0 then
+        if not util.bufname_valid(bufname) then
+          return
+        end
       end
       local buf_path = util.path.sanitize(bufname)
 
@@ -247,7 +255,7 @@ function configs.__newindex(t, config_name, config_def)
       if root_dir then
         id = manager.add(root_dir, false)
       elseif config.single_file_support then
-        local pseudo_root = util.path.dirname(buf_path)
+        local pseudo_root = #bufname == 0 and uv.cmd() or util.path.dirname(buf_path)
         id = manager.add(pseudo_root, true)
       end
 
diff --git a/lua/lspconfig/util.lua b/lua/lspconfig/util.lua
index f8a359f0..a1f04bec 100644
--- a/lua/lspconfig/util.lua
+++ b/lua/lspconfig/util.lua
@@ -20,9 +20,6 @@ M.default_config = {
 M.on_setup = nil
 
 function M.bufname_valid(bufname)
-  if not bufname then
-    return false
-  end
   if bufname:match '^/' or bufname:match '^[a-zA-Z]:' or bufname:match '^zipfile://' or bufname:match '^tarfile:' then
     return true
   end