Bind 'SPC b u' to save current file as root

core/autoload/files.el

@@ -341,3 +341,15 @@ file if it exists, without confirmation."
   "Open the current file as root."
   (interactive)
   (find-alternate-file (doom--sudo-file buffer-file-name)))
+
+;;;###autoload
+(defun doom/sudo-save-buffer ()
+  "Save this file as root."
+  (interactive)
+  (let ((origin (current-buffer))
+        (buffer (doom--sudo-file buffer-file-name)))
+    (unwind-protect
+        (with-current-buffer buffer
+          (save-buffer))
+      (unless (eq origin buffer)
+        (kill-buffer buffer)))))

modules/config/default/+evil-bindings.el

@@ -340,6 +340,7 @@
         :desc "Revert buffer"               "r"   #'revert-buffer
         :desc "Save buffer"                 "s"   #'basic-save-buffer
         :desc "Save all buffers"            "S"   #'evil-write-all
+        :desc "Save buffer as root"         "u"   #'doom/sudo-save-buffer
         :desc "Pop up scratch buffer"       "x"   #'doom/open-scratch-buffer
         :desc "Switch to scratch buffer"    "X"   #'doom/switch-to-scratch-buffer
         :desc "Bury buffer"                 "z"   #'bury-buffer