fix(lsp): improve LSP floating preview window cleanup #31353

Problem: The current implementation creates a unique autocommand group for each floating preview window, which is inefficient and can lead to numerous autocommand groups.

Solution: Use a single shared autocommand group with improved window validation to properly clean up LSP floating preview windows.

runtime/lua/vim/lsp/util.lua

@@ -1622,23 +1622,24 @@ function M.open_floating_preview(contents, syntax, opts)
       api.nvim_win_set_var(floating_winnr, opts.focus_id, bufnr)
     end
     api.nvim_buf_set_var(bufnr, 'lsp_floating_preview', floating_winnr)
+    api.nvim_win_set_var(floating_winnr, 'lsp_floating_bufnr', bufnr)
   end
 
-  local augroup_name = ('nvim.closing_floating_preview_%d'):format(floating_winnr)
-  local ok =
-    pcall(api.nvim_get_autocmds, { group = augroup_name, pattern = tostring(floating_winnr) })
-  if not ok then
   api.nvim_create_autocmd('WinClosed', {
-      group = api.nvim_create_augroup(augroup_name, {}),
+    group = api.nvim_create_augroup('nvim.closing_floating_preview', { clear = true }),
-      pattern = tostring(floating_winnr),
+    callback = function(args)
-      callback = function()
+      local winid = tonumber(args.match)
-        if api.nvim_buf_is_valid(bufnr) then
+      local ok, preview_bufnr = pcall(api.nvim_win_get_var, winid, 'lsp_floating_bufnr')
+      if
+        ok
+        and api.nvim_buf_is_valid(preview_bufnr)
+        and winid == vim.b[preview_bufnr].lsp_floating_preview
+      then
         vim.b[bufnr].lsp_floating_preview = nil
+        return true
       end
-        api.nvim_del_augroup_by_name(augroup_name)
     end,
   })
-  end
 
   vim.wo[floating_winnr].foldenable = false -- Disable folding.
   vim.wo[floating_winnr].wrap = opts.wrap -- Soft wrapping.

test/functional/plugin/lsp/utils_spec.lua

@@ -267,8 +267,16 @@ describe('vim.lsp.util', function()
 
         eq(56, opts.height)
       end)
+    end)
+  end)
+
+  describe('open_floating_preview', function()
+    before_each(function()
+      n.clear()
+      Screen.new(10, 10)
+      feed('9i<CR><Esc>G4k')
+    end)
 
-      describe('vim.lsp.util.open_floating_preview', function()
     local var_name = 'lsp_floating_preview'
     local curbuf = api.nvim_get_current_buf()
 
@@ -278,10 +286,7 @@ describe('vim.lsp.util', function()
       end)
       eq(true, api.nvim_win_is_valid(api.nvim_buf_get_var(curbuf, var_name)))
       command('fclose')
-          eq(
+      eq('Key not found: lsp_floating_preview', pcall_err(api.nvim_buf_get_var, curbuf, var_name))
-            'Key not found: lsp_floating_preview',
-            pcall_err(api.nvim_buf_get_var, curbuf, var_name)
-          )
     end)
 
     it('clean bufvar after CursorMoved', function()
@@ -293,12 +298,7 @@ describe('vim.lsp.util', function()
         return result
       end)
       eq(true, result)
-          eq(
+      eq('Key not found: lsp_floating_preview', pcall_err(api.nvim_buf_get_var, curbuf, var_name))
-            'Key not found: lsp_floating_preview',
-            pcall_err(api.nvim_buf_get_var, curbuf, var_name)
-          )
-        end)
-      end)
     end)
   end)