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.

2 files changed, 45 insertions, 44 deletions

diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index ef177e903f..307a55c2a2 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/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, {}),
-      pattern = tostring(floating_winnr),
-      callback = function()
-        if api.nvim_buf_is_valid(bufnr) then
-          vim.b[bufnr].lsp_floating_preview = nil
-        end
-        api.nvim_del_augroup_by_name(augroup_name)
-      end,
-    })
-  end
+  api.nvim_create_autocmd('WinClosed', {
+    group = api.nvim_create_augroup('nvim.closing_floating_preview', { clear = true }),
+    callback = function(args)
+      local winid = tonumber(args.match)
+      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
+    end,
+  })
 
   vim.wo[floating_winnr].foldenable = false -- Disable folding.
   vim.wo[floating_winnr].wrap = opts.wrap -- Soft wrapping.
diff --git a/test/functional/plugin/lsp/utils_spec.lua b/test/functional/plugin/lsp/utils_spec.lua
index 7bfb354c2e..fac9a2c69d 100644
--- a/test/functional/plugin/lsp/utils_spec.lua
+++ b/test/functional/plugin/lsp/utils_spec.lua
@@ -267,38 +267,38 @@ describe('vim.lsp.util', function()
 
         eq(56, opts.height)
       end)
+    end)
+  end)
 
-      describe('vim.lsp.util.open_floating_preview', function()
-        local var_name = 'lsp_floating_preview'
-        local curbuf = api.nvim_get_current_buf()
-
-        it('clean bufvar after fclose', function()
-          exec_lua(function()
-            vim.lsp.util.open_floating_preview({ 'test' }, '', { height = 5, width = 2 })
-          end)
-          eq(true, api.nvim_win_is_valid(api.nvim_buf_get_var(curbuf, var_name)))
-          command('fclose')
-          eq(
-            'Key not found: lsp_floating_preview',
-            pcall_err(api.nvim_buf_get_var, curbuf, var_name)
-          )
-        end)
+  describe('open_floating_preview', function()
+    before_each(function()
+      n.clear()
+      Screen.new(10, 10)
+      feed('9i<CR><Esc>G4k')
+    end)
 
-        it('clean bufvar after CursorMoved', function()
-          local result = exec_lua(function()
-            vim.lsp.util.open_floating_preview({ 'test' }, '', { height = 5, width = 2 })
-            local winnr = vim.b[vim.api.nvim_get_current_buf()].lsp_floating_preview
-            local result = vim.api.nvim_win_is_valid(winnr)
-            vim.api.nvim_feedkeys(vim.keycode('G'), 'txn', false)
-            return result
-          end)
-          eq(true, result)
-          eq(
-            'Key not found: lsp_floating_preview',
-            pcall_err(api.nvim_buf_get_var, curbuf, var_name)
-          )
-        end)
+    local var_name = 'lsp_floating_preview'
+    local curbuf = api.nvim_get_current_buf()
+
+    it('clean bufvar after fclose', function()
+      exec_lua(function()
+        vim.lsp.util.open_floating_preview({ 'test' }, '', { height = 5, width = 2 })
+      end)
+      eq(true, api.nvim_win_is_valid(api.nvim_buf_get_var(curbuf, var_name)))
+      command('fclose')
+      eq('Key not found: lsp_floating_preview', pcall_err(api.nvim_buf_get_var, curbuf, var_name))
+    end)
+
+    it('clean bufvar after CursorMoved', function()
+      local result = exec_lua(function()
+        vim.lsp.util.open_floating_preview({ 'test' }, '', { height = 5, width = 2 })
+        local winnr = vim.b[vim.api.nvim_get_current_buf()].lsp_floating_preview
+        local result = vim.api.nvim_win_is_valid(winnr)
+        vim.api.nvim_feedkeys(vim.keycode('G'), 'txn', false)
+        return result
       end)
+      eq(true, result)
+      eq('Key not found: lsp_floating_preview', pcall_err(api.nvim_buf_get_var, curbuf, var_name))
     end)
   end)