refactor(comments): extract shared comment-syntax resolution

The comment-start/comment-end resolution was copied into six command wrappers. One cj/--comment-read-syntax now owns it; the block-banner wrapper keeps its own block-specific prompt.

2 files changed, 55 insertions, 36 deletions

diff --git a/modules/custom-comments.el b/modules/custom-comments.el
index 7f66424c..2e77af5a 100644
--- a/modules/custom-comments.el
+++ b/modules/custom-comments.el
@@ -72,6 +72,18 @@ is the line-opening prologue shared by the divider and inline-border emitters."
   (when (equal cmt-start ";") (insert cmt-start))
   (insert " "))
 
+(defun cj/--comment-read-syntax ()
+  "Return the buffer's comment syntax as a cons (COMMENT-START . COMMENT-END).
+Falls back to prompting for the start when the buffer has none, and to an
+empty end string.  The single source of the resolution that was previously
+copied into each command wrapper."
+  (cons (if (and (boundp 'comment-start) comment-start)
+            comment-start
+          (read-string "Comment start character(s): "))
+        (if (and (boundp 'comment-end) comment-end)
+            comment-end
+          "")))
+
 ;; ----------------------------- Inline Border ---------------------------------
 
 (defun cj/--comment-inline-border (cmt-start cmt-end decoration-char text length)
@@ -129,12 +141,9 @@ LENGTH is the total width of the line."
 DECORATION-CHAR defaults to \"#\" if not provided.
 Uses the lesser of `fill-column\\=' or 80 for line length."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (decoration-char (or decoration-char "#"))
          (text (capitalize (string-trim (read-from-minibuffer "Comment: "))))
          (length (min fill-column 80)))
@@ -157,12 +166,9 @@ delegates to `cj/--comment-padded-divider' with PADDING 0."
   "Insert a simple divider comment banner.
 Prompts for decoration character, text, and length option."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (decoration-char (read-string "Decoration character (default =): " nil nil "="))
          (text (read-string "Comment text: "))
          (length-option (completing-read "Comment length: "
@@ -237,12 +243,9 @@ PADDING is the number of spaces before the text."
   "Insert a padded divider comment banner.
 Prompts for decoration character, text, padding, and length option."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (decoration-char (read-string "Decoration character (default =): " nil nil "="))
          (text (read-string "Comment text: "))
          (padding (string-to-number (read-string "Padding spaces (default 2): " nil nil "2")))
@@ -338,12 +341,9 @@ LENGTH is the total width of each line."
   "Insert a 3-line comment box with centered text.
 Prompts for decoration character, text, and uses `fill-column' for length."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (decoration-char (read-string "Decoration character (default -): " nil nil "-"))
          (text (capitalize (string-trim (read-from-minibuffer "Comment: "))))
          (length (min fill-column 80)))
@@ -366,12 +366,9 @@ text, so it delegates to `cj/--comment-box-emit' with HEAVY non-nil."
   "Insert a heavy box comment with blank lines around centered text.
 Prompts for decoration character, text, and length option."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (decoration-char (read-string "Decoration character (default *): " nil nil "*"))
          (text (read-string "Comment text: "))
          (length-option (completing-read "Comment length: "
@@ -449,12 +446,9 @@ BOX-STYLE is either \\='single or \\='double for line style."
   "Insert a unicode box comment.
 Prompts for text, box style, and length option."
   (interactive)
-  (let* ((comment-start (if (and (boundp 'comment-start) comment-start)
-                           comment-start
-                         (read-string "Comment start character(s): ")))
-         (comment-end (if (and (boundp 'comment-end) comment-end)
-                         comment-end
-                       ""))
+  (let* ((comment-syntax (cj/--comment-read-syntax))
+         (comment-start (car comment-syntax))
+         (comment-end (cdr comment-syntax))
          (text (read-string "Comment text: "))
          (box-style (intern (completing-read "Comment box style: "
                                              '("single" "double")
diff --git a/tests/test-custom-comments-public-wrappers.el b/tests/test-custom-comments-public-wrappers.el
index 42842649..2eda9d94 100644
--- a/tests/test-custom-comments-public-wrappers.el
+++ b/tests/test-custom-comments-public-wrappers.el
@@ -188,5 +188,30 @@ text via `read-from-minibuffer'."
     (cj/comment-block-banner)
     (should (string-match-p "Banner" (buffer-string)))))
 
+;;; cj/--comment-read-syntax — the shared comment-syntax resolution
+
+(ert-deftest test-comment-read-syntax-uses-buffer-syntax ()
+  "Normal: a buffer with comment syntax resolves without prompting."
+  (with-temp-buffer
+    (setq-local comment-start ";")
+    (setq-local comment-end "")
+    (cl-letf (((symbol-function 'read-string)
+               (lambda (&rest _) (error "should not prompt"))))
+      (should (equal (cj/--comment-read-syntax) '(";" . ""))))))
+
+(ert-deftest test-comment-read-syntax-nil-end-falls-back-to-empty ()
+  "Boundary: a nil comment-end resolves to the empty string."
+  (with-temp-buffer
+    (setq-local comment-start "#")
+    (setq-local comment-end nil)
+    (should (equal (cj/--comment-read-syntax) '("#" . "")))))
+
+(ert-deftest test-comment-read-syntax-prompts-when-unset ()
+  "Error: no buffer comment-start falls back to the prompt."
+  (with-temp-buffer
+    (setq-local comment-start nil)
+    (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "//")))
+      (should (equal (car (cj/--comment-read-syntax)) "//")))))
+
 (provide 'test-custom-comments-public-wrappers)
 ;;; test-custom-comments-public-wrappers.el ends here