Add a function wrap and unwrap with the dbg! macro.

Author: r-darwish

rust-mode-tests.el

@@ -245,6 +245,10 @@ fn bar() { }"
 /// even more.
 fn bar() { }" 14 85))
 
+(defun test-dbg-wrap (initial expected position &optional end)
+  (with-temp-buffer
+    (insert initial)))
+
 (defun test-auto-fill (initial position inserted expected)
   (rust-test-manip-code
    initial
@@ -3138,6 +3142,50 @@ impl Two<'a> {
      "Foo" font-lock-type-face
      "in" font-lock-keyword-face)))
 
+(ert-deftest rust-test-dbg-wrap-symbol ()
+  (rust-test-manip-code
+   "let x = add(first, second);"
+   15
+   #'rust-dbg-wrap-or-unwrap
+   "let x = add(dbg!(first), second);"))
+
+(ert-deftest rust-test-dbg-wrap-symbol-unbalanced ()
+  (rust-test-manip-code
+   "let x = add((first, second);"
+   14
+   #'rust-dbg-wrap-or-unwrap
+   "let x = add((dbg!(first), second);"))
+
+(ert-deftest rust-test-dbg-wrap-region ()
+  (rust-test-manip-code
+   "let x = add(first, second);"
+   9
+   (lambda ()
+     (transient-mark-mode 1)
+     (push-mark nil t t)
+     (goto-char 26)
+     (rust-dbg-wrap-or-unwrap))
+   "let x = dbg!(add(first, second));"))
+
+(defun rust-test-dbg-unwrap (position)
+  (rust-test-manip-code
+   "let x = add(dbg!(first), second);"
+   position
+   #'rust-dbg-wrap-or-unwrap
+   "let x = add(first, second);"))
+
+(ert-deftest rust-test-dbg-uwnrap-within ()
+  (rust-test-dbg-unwrap 19))
+
+(ert-deftest rust-test-dbg-uwnrap-on-paren ()
+  (rust-test-dbg-unwrap 17))
+
+(ert-deftest rust-test-dbg-uwnrap-on-dbg-middle ()
+  (rust-test-dbg-unwrap 15))
+
+(ert-deftest rust-test-dbg-uwnrap-on-dbg-start ()
+  (rust-test-dbg-unwrap 13))
+
 (when (executable-find rust-cargo-bin)
   (ert-deftest rust-test-project-located ()
     (lexical-let* ((test-dir (expand-file-name "test-project/" default-directory))

rust-mode.el

@@ -19,6 +19,7 @@
                    (require 'url-vars))
 
 (require 'json)
+(require 'thingatpt)
 
 (defvar electric-pair-inhibit-predicate)
 (defvar electric-pair-skip-self)
@@ -1582,6 +1583,7 @@ Return the created process."
 (defvar rust-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "C-c C-f") 'rust-format-buffer)
+    (define-key map (kbd "C-c d") 'rust-dbg-wrap-or-unwrap)
     map)
   "Keymap for Rust major mode.")
 
@@ -1800,6 +1802,42 @@ visit the new file."
       (let ((output (json-read)))
         (cdr (assoc-string "root" output))))))
 
+(defun rust-insert-dbg ()
+  "Insert the dbg! macro."
+  (cond ((region-active-p)
+         (insert-parentheses)
+         (backward-char 1))
+        (t
+         (insert "(")
+         (forward-sexp)
+         (insert ")")
+         (backward-sexp)))
+  (insert "dbg!"))
+
+;;;###autoload
+(defun rust-dbg-wrap-or-unwrap ()
+  "Either remove or add the dbg! macro."
+  (interactive)
+  (save-excursion
+    (if (region-active-p)
+        (rust-insert-dbg)
+
+      (let ((beginning-of-symbol (ignore-errors (beginning-of-thing 'symbol))))
+        (when beginning-of-symbol
+          (goto-char beginning-of-symbol)))
+
+      (let ((dbg-point (save-excursion
+                         (or (and (looking-at-p "dbg!") (+ 4 (point)))
+                             (ignore-errors
+                               (while (not (rust-looking-back-str "dbg!"))
+                                 (backward-up-list))
+                               (point))))))
+        (cond (dbg-point
+               (goto-char dbg-point)
+               (delete-char -4)
+               (delete-pair))
+              (t (rust-insert-dbg)))))))
+
 (provide 'rust-mode)
 
 ;;; rust-mode.el ends here