refactor(mail): extract the mu4e attachment workflow into its own module

The attachment-save UI (the MIME-part filters, the three save commands, and the `special-mode'-derived selection buffer) was ~230 lines in `mail-config.el' and depended on nothing else there. It moves to `modules/mu4e-attachments.el', which `mail-config' now requires. `cj/email-map' and its C-; e bindings stay put. The keymap just points at commands that now live next door.

The unit tests move with it: `test-mail-config-attachments.el' becomes `test-mu4e-attachments.el' and requires the new module directly instead of pulling in the whole mu4e and org-msg use-package stack. The two tests that check `cj/email-map' wiring move to a new `test-mail-config.el', since that map belongs to `mail-config'. One of the moved tests quietly relied on a real mu4e install (it loaded `mu4e-mime-parts' through a load-path entry that loading `mail-config' happens to add), so it now stubs that path itself.

4 files changed, 341 insertions, 308 deletions

diff --git a/modules/mail-config.el b/modules/mail-config.el
index 9d428209..4dbd6fb2 100644
--- a/modules/mail-config.el
+++ b/modules/mail-config.el
@@ -7,10 +7,8 @@
 ;;
 ;; https://macowners.club/posts/email-emacs-mu4e-macos/
 ;;
-;; Attachment saving:
-;; - C-; e S saves all attachments from the current mu4e view message.
-;; - C-; e s prompts for one attachment and saves it.
-;; Both commands prompt for a destination directory.
+;; Attachment saving lives in the `mu4e-attachments' module; its C-; e
+;; bindings are wired into `cj/email-map' below.
 ;;
 ;; Crash Fix:
 ;; auto-composition-mode is disabled in mu4e-headers-mode to prevent a
@@ -22,7 +20,7 @@
 
 (require 'user-constants)
 (require 'system-lib)
-(require 'seq)
+(require 'mu4e-attachments)
 
 ;; cj/custom-keymap's real binding is in keybindings.el, which init.el loads
 ;; first. The use-package org-msg :preface below wraps in eval-and-compile, so
@@ -37,15 +35,6 @@
 (defvar send-mail-function nil)
 (defvar message-send-mail-function nil)
 (defvar message-sendmail-envelope-from nil)
-(defvar mu4e-uniquify-save-file-name-function)
-(defvar-local cj/mu4e-attachment-selection-directory nil
-  "Destination directory for the current attachment selection buffer.")
-(defvar-local cj/mu4e-attachment-selection-entries nil
-  "Attachment selection entries for the current selection buffer.")
-
-(declare-function mm-save-part-to-file "mm-decode" (handle filename))
-(declare-function mu4e-join-paths "mu4e-helpers" (directory &rest components))
-(declare-function mu4e-view-mime-parts "mu4e-mime-parts" ())
 
 (defcustom cj/smtpmail-debug-enabled nil
   "Non-nil means enable verbose SMTP transport debug logging.
@@ -87,221 +76,6 @@ transport details in debug buffers."
             message-sendmail-envelope-from 'header)
     (setq sendmail-program nil)))
 
-;; --------------------------- Attachment Saving ------------------------------
-
-(defun cj/mu4e--attachment-parts (&optional parts)
-  "Return attachment-like MIME PARTS for the current mu4e view message.
-When PARTS is nil, read parts from `mu4e-view-mime-parts'."
-  (seq-filter (lambda (part) (plist-get part :attachment-like))
-              (or parts
-                  (progn
-                    (unless (fboundp 'mu4e-view-mime-parts)
-                      (require 'mu4e-mime-parts))
-                    (mu4e-view-mime-parts)))))
-
-(defun cj/mu4e--attachment-duplicate-filenames (parts)
-  "Return filenames that appear more than once in PARTS."
-  (let ((counts (make-hash-table :test 'equal))
-        duplicates)
-    (dolist (part parts)
-      (let ((filename (plist-get part :filename)))
-        (puthash filename (1+ (gethash filename counts 0)) counts)))
-    (maphash (lambda (filename count)
-               (when (> count 1)
-                 (push filename duplicates)))
-             counts)
-    duplicates))
-
-(defun cj/mu4e--attachment-label (part duplicate-filenames)
-  "Return a completion label for PART.
-DUPLICATE-FILENAMES is a list of filenames that need part-index disambiguation."
-  (let ((filename (or (plist-get part :filename) "unnamed-attachment")))
-    (if (member filename duplicate-filenames)
-        (format "%s <part %s>" filename (plist-get part :part-index))
-      filename)))
-
-(defun cj/mu4e--attachment-candidates (parts)
-  "Return completion candidates for attachment PARTS.
-The result is an alist of display labels to MIME part plists."
-  (let ((duplicates (cj/mu4e--attachment-duplicate-filenames parts)))
-    (mapcar (lambda (part)
-              (cons (cj/mu4e--attachment-label part duplicates) part))
-            parts)))
-
-(defun cj/mu4e--attachment-default-directory (parts)
-  "Return a sensible default save directory for attachment PARTS."
-  (file-name-as-directory
-   (or (plist-get (car parts) :target-dir)
-       (expand-file-name "~/Downloads/"))))
-
-(defun cj/mu4e--read-attachment-directory (parts)
-  "Prompt for a destination directory for attachment PARTS."
-  (file-name-as-directory
-   (read-directory-name "Save attachments to: "
-                        (cj/mu4e--attachment-default-directory parts))))
-
-(defun cj/mu4e--ensure-attachment-save-functions ()
-  "Load mu4e MIME support when attachment save helpers need it."
-  (unless (and (boundp 'mu4e-uniquify-save-file-name-function)
-               (fboundp 'mu4e-join-paths))
-    (require 'mu4e-mime-parts)))
-
-(defun cj/mu4e--save-attachment-part (part directory)
-  "Save attachment PART to DIRECTORY and return the final path."
-  (cj/mu4e--ensure-attachment-save-functions)
-  (let ((handle (plist-get part :handle)))
-    (unless handle
-      (user-error "Attachment has no MIME handle: %s"
-                  (or (plist-get part :filename) "<unnamed>")))
-    (let* ((path (funcall mu4e-uniquify-save-file-name-function
-                          (mu4e-join-paths directory
-                                           (plist-get part :filename)))))
-      (mm-save-part-to-file handle path)
-      path)))
-
-(defun cj/mu4e--save-attachment-parts (parts directory)
-  "Save attachment PARTS to DIRECTORY and return the saved paths."
-  (mapcar (lambda (part)
-            (cj/mu4e--save-attachment-part part directory))
-          parts))
-
-(defun cj/mu4e-save-all-attachments ()
-  "Prompt for a directory and save all attachments in the current mu4e message."
-  (interactive)
-  (let ((parts (cj/mu4e--attachment-parts)))
-    (unless parts
-      (user-error "No attachments for this message"))
-    (let* ((directory (cj/mu4e--read-attachment-directory parts))
-           (paths (cj/mu4e--save-attachment-parts parts directory)))
-      (message "Saved %d attachment%s to %s"
-               (length paths)
-               (if (= (length paths) 1) "" "s")
-               directory)
-      paths)))
-
-(defun cj/mu4e-save-attachment-here ()
-  "Prompt for one attachment and a directory, then save that attachment."
-  (interactive)
-  (let ((parts (cj/mu4e--attachment-parts)))
-    (unless parts
-      (user-error "No attachments for this message"))
-    (let* ((directory (cj/mu4e--read-attachment-directory parts))
-           (candidates (cj/mu4e--attachment-candidates parts))
-           (choice (completing-read "Save attachment: " candidates nil t))
-           (part (cdr (assoc choice candidates)))
-           (path (cj/mu4e--save-attachment-part part directory)))
-      (message "Saved attachment to %s" path)
-      path)))
-
-(defvar cj/mu4e-attachment-selection-mode-map
-  (let ((map (make-sparse-keymap)))
-    (define-key map (kbd "RET") #'cj/mu4e-attachment-selection-toggle)
-    (define-key map (kbd "a") #'cj/mu4e-attachment-selection-mark-all)
-    (define-key map (kbd "u") #'cj/mu4e-attachment-selection-unmark-all)
-    (define-key map (kbd "s") #'cj/mu4e-attachment-selection-save-marked)
-    (define-key map (kbd "q") #'quit-window)
-    map)
-  "Keymap for `cj/mu4e-attachment-selection-mode'.")
-
-(define-derived-mode cj/mu4e-attachment-selection-mode special-mode "Mail Attachments"
-  "Mode for selecting mu4e attachments to save.")
-
-(defun cj/mu4e--attachment-selection-entry-at-point ()
-  "Return the attachment selection entry at point."
-  (or (get-text-property (point) 'cj/mu4e-attachment-entry)
-      (get-text-property (line-beginning-position) 'cj/mu4e-attachment-entry)
-      (user-error "No attachment on this line")))
-
-(defun cj/mu4e--attachment-selection-render ()
-  "Render the current attachment selection buffer."
-  (let ((inhibit-read-only t)
-        (point-line (line-number-at-pos)))
-    (erase-buffer)
-    (insert (format "Save attachments to: %s\n\n"
-                    cj/mu4e-attachment-selection-directory))
-    (insert "RET toggle   a mark all   u unmark all   s save marked   q quit\n\n")
-    (dolist (entry cj/mu4e-attachment-selection-entries)
-      (let* ((part (plist-get entry :part))
-             (mark (if (plist-get entry :selected) "[x]" "[ ]"))
-             (label (plist-get entry :label))
-             (mime-type (or (plist-get part :mime-type) ""))
-             (size (if-let ((bytes (plist-get part :decoded-size-approx)))
-                       (file-size-human-readable bytes)
-                     "")))
-        (insert
-         (propertize
-          (format "%s %-40s %-24s %s\n" mark label mime-type size)
-          'cj/mu4e-attachment-entry entry))))
-    (goto-char (point-min))
-    (forward-line (max 0 (1- point-line)))))
-
-(defun cj/mu4e--attachment-selection-setup (parts directory)
-  "Populate the current selection buffer with attachment PARTS and DIRECTORY."
-  (setq cj/mu4e-attachment-selection-directory directory)
-  (setq cj/mu4e-attachment-selection-entries
-        (mapcar (lambda (candidate)
-                  (list :label (car candidate)
-                        :part (cdr candidate)
-                        :selected nil))
-                (cj/mu4e--attachment-candidates parts)))
-  (cj/mu4e--attachment-selection-render))
-
-(defun cj/mu4e-attachment-selection-toggle ()
-  "Toggle the attachment entry at point."
-  (interactive)
-  (let ((entry (cj/mu4e--attachment-selection-entry-at-point)))
-    (setf (plist-get entry :selected)
-          (not (plist-get entry :selected)))
-    (cj/mu4e--attachment-selection-render)))
-
-(defun cj/mu4e-attachment-selection-mark-all ()
-  "Mark all attachments in the selection buffer."
-  (interactive)
-  (dolist (entry cj/mu4e-attachment-selection-entries)
-    (setf (plist-get entry :selected) t))
-  (cj/mu4e--attachment-selection-render))
-
-(defun cj/mu4e-attachment-selection-unmark-all ()
-  "Unmark all attachments in the selection buffer."
-  (interactive)
-  (dolist (entry cj/mu4e-attachment-selection-entries)
-    (setf (plist-get entry :selected) nil))
-  (cj/mu4e--attachment-selection-render))
-
-(defun cj/mu4e-attachment-selection-save-marked ()
-  "Save marked attachments from the selection buffer."
-  (interactive)
-  (let ((parts (mapcar (lambda (entry) (plist-get entry :part))
-                       (seq-filter (lambda (entry)
-                                     (plist-get entry :selected))
-                                   cj/mu4e-attachment-selection-entries))))
-    (unless parts
-      (user-error "No attachments selected"))
-    (let ((paths (cj/mu4e--save-attachment-parts
-                  parts cj/mu4e-attachment-selection-directory)))
-      (message "Saved %d attachment%s to %s"
-               (length paths)
-               (if (= (length paths) 1) "" "s")
-               cj/mu4e-attachment-selection-directory)
-      paths)))
-
-(defun cj/mu4e--open-attachment-selection-buffer (parts directory)
-  "Open an attachment selection buffer for PARTS and DIRECTORY."
-  (let ((buffer (get-buffer-create "*mu4e attachments*")))
-    (with-current-buffer buffer
-      (cj/mu4e-attachment-selection-mode)
-      (cj/mu4e--attachment-selection-setup parts directory))
-    (pop-to-buffer buffer)))
-
-(defun cj/mu4e-save-some-attachments ()
-  "Prompt for a directory and open a buffer to select attachments to save."
-  (interactive)
-  (let ((parts (cj/mu4e--attachment-parts)))
-    (unless parts
-      (user-error "No attachments for this message"))
-    (let ((directory (cj/mu4e--read-attachment-directory parts)))
-      (cj/mu4e--open-attachment-selection-buffer parts directory))))
-
 ;; -------------------- HarfBuzz Crash Fix: Disable Composition ---------------
 ;; Disable auto-composition in mu4e headers to prevent SIGSEGV from HarfBuzz
 ;; when shaping emoji characters in email subjects. See Commentary above.
diff --git a/modules/mu4e-attachments.el b/modules/mu4e-attachments.el
new file mode 100644
index 00000000..87392681
--- /dev/null
+++ b/modules/mu4e-attachments.el
@@ -0,0 +1,245 @@
+;;; mu4e-attachments.el --- Save attachments from mu4e view messages -*- lexical-binding: t; coding: utf-8; -*-
+;; author Craig Jennings <c@cjennings.net>
+;;
+;;; Commentary:
+;; Project-owned commands for saving attachments out of a mu4e message view.
+;;
+;; - `cj/mu4e-save-all-attachments' saves every attachment.
+;; - `cj/mu4e-save-attachment-here' prompts for one attachment and saves it.
+;; - `cj/mu4e-save-some-attachments' opens a selection buffer: RET toggles a
+;;   row, a marks all, u unmarks all, s saves the marked rows, q quits.
+;; All three prompt for a destination directory.
+;;
+;; The keybindings live in `mail-config' under `cj/email-map' (C-; e).
+
+;;; Code:
+
+(require 'seq)
+
+(defvar mu4e-uniquify-save-file-name-function)
+(defvar-local cj/mu4e-attachment-selection-directory nil
+  "Destination directory for the current attachment selection buffer.")
+(defvar-local cj/mu4e-attachment-selection-entries nil
+  "Attachment selection entries for the current selection buffer.")
+
+(declare-function mm-save-part-to-file "mm-decode" (handle filename))
+(declare-function mu4e-join-paths "mu4e-helpers" (directory &rest components))
+(declare-function mu4e-view-mime-parts "mu4e-mime-parts" ())
+
+;; --------------------------- Attachment Saving ------------------------------
+
+(defun cj/mu4e--attachment-parts (&optional parts)
+  "Return attachment-like MIME PARTS for the current mu4e view message.
+When PARTS is nil, read parts from `mu4e-view-mime-parts'."
+  (seq-filter (lambda (part) (plist-get part :attachment-like))
+              (or parts
+                  (progn
+                    (unless (fboundp 'mu4e-view-mime-parts)
+                      (require 'mu4e-mime-parts))
+                    (mu4e-view-mime-parts)))))
+
+(defun cj/mu4e--attachment-duplicate-filenames (parts)
+  "Return filenames that appear more than once in PARTS."
+  (let ((counts (make-hash-table :test 'equal))
+        duplicates)
+    (dolist (part parts)
+      (let ((filename (plist-get part :filename)))
+        (puthash filename (1+ (gethash filename counts 0)) counts)))
+    (maphash (lambda (filename count)
+               (when (> count 1)
+                 (push filename duplicates)))
+             counts)
+    duplicates))
+
+(defun cj/mu4e--attachment-label (part duplicate-filenames)
+  "Return a completion label for PART.
+DUPLICATE-FILENAMES is a list of filenames that need part-index disambiguation."
+  (let ((filename (or (plist-get part :filename) "unnamed-attachment")))
+    (if (member filename duplicate-filenames)
+        (format "%s <part %s>" filename (plist-get part :part-index))
+      filename)))
+
+(defun cj/mu4e--attachment-candidates (parts)
+  "Return completion candidates for attachment PARTS.
+The result is an alist of display labels to MIME part plists."
+  (let ((duplicates (cj/mu4e--attachment-duplicate-filenames parts)))
+    (mapcar (lambda (part)
+              (cons (cj/mu4e--attachment-label part duplicates) part))
+            parts)))
+
+(defun cj/mu4e--attachment-default-directory (parts)
+  "Return a sensible default save directory for attachment PARTS."
+  (file-name-as-directory
+   (or (plist-get (car parts) :target-dir)
+       (expand-file-name "~/Downloads/"))))
+
+(defun cj/mu4e--read-attachment-directory (parts)
+  "Prompt for a destination directory for attachment PARTS."
+  (file-name-as-directory
+   (read-directory-name "Save attachments to: "
+                        (cj/mu4e--attachment-default-directory parts))))
+
+(defun cj/mu4e--ensure-attachment-save-functions ()
+  "Load mu4e MIME support when attachment save helpers need it."
+  (unless (and (boundp 'mu4e-uniquify-save-file-name-function)
+               (fboundp 'mu4e-join-paths))
+    (require 'mu4e-mime-parts)))
+
+(defun cj/mu4e--save-attachment-part (part directory)
+  "Save attachment PART to DIRECTORY and return the final path."
+  (cj/mu4e--ensure-attachment-save-functions)
+  (let ((handle (plist-get part :handle)))
+    (unless handle
+      (user-error "Attachment has no MIME handle: %s"
+                  (or (plist-get part :filename) "<unnamed>")))
+    (let* ((path (funcall mu4e-uniquify-save-file-name-function
+                          (mu4e-join-paths directory
+                                           (plist-get part :filename)))))
+      (mm-save-part-to-file handle path)
+      path)))
+
+(defun cj/mu4e--save-attachment-parts (parts directory)
+  "Save attachment PARTS to DIRECTORY and return the saved paths."
+  (mapcar (lambda (part)
+            (cj/mu4e--save-attachment-part part directory))
+          parts))
+
+(defun cj/mu4e-save-all-attachments ()
+  "Prompt for a directory and save all attachments in the current mu4e message."
+  (interactive)
+  (let ((parts (cj/mu4e--attachment-parts)))
+    (unless parts
+      (user-error "No attachments for this message"))
+    (let* ((directory (cj/mu4e--read-attachment-directory parts))
+           (paths (cj/mu4e--save-attachment-parts parts directory)))
+      (message "Saved %d attachment%s to %s"
+               (length paths)
+               (if (= (length paths) 1) "" "s")
+               directory)
+      paths)))
+
+(defun cj/mu4e-save-attachment-here ()
+  "Prompt for one attachment and a directory, then save that attachment."
+  (interactive)
+  (let ((parts (cj/mu4e--attachment-parts)))
+    (unless parts
+      (user-error "No attachments for this message"))
+    (let* ((directory (cj/mu4e--read-attachment-directory parts))
+           (candidates (cj/mu4e--attachment-candidates parts))
+           (choice (completing-read "Save attachment: " candidates nil t))
+           (part (cdr (assoc choice candidates)))
+           (path (cj/mu4e--save-attachment-part part directory)))
+      (message "Saved attachment to %s" path)
+      path)))
+
+(defvar cj/mu4e-attachment-selection-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map (kbd "RET") #'cj/mu4e-attachment-selection-toggle)
+    (define-key map (kbd "a") #'cj/mu4e-attachment-selection-mark-all)
+    (define-key map (kbd "u") #'cj/mu4e-attachment-selection-unmark-all)
+    (define-key map (kbd "s") #'cj/mu4e-attachment-selection-save-marked)
+    (define-key map (kbd "q") #'quit-window)
+    map)
+  "Keymap for `cj/mu4e-attachment-selection-mode'.")
+
+(define-derived-mode cj/mu4e-attachment-selection-mode special-mode "Mail Attachments"
+  "Mode for selecting mu4e attachments to save.")
+
+(defun cj/mu4e--attachment-selection-entry-at-point ()
+  "Return the attachment selection entry at point."
+  (or (get-text-property (point) 'cj/mu4e-attachment-entry)
+      (get-text-property (line-beginning-position) 'cj/mu4e-attachment-entry)
+      (user-error "No attachment on this line")))
+
+(defun cj/mu4e--attachment-selection-render ()
+  "Render the current attachment selection buffer."
+  (let ((inhibit-read-only t)
+        (point-line (line-number-at-pos)))
+    (erase-buffer)
+    (insert (format "Save attachments to: %s\n\n"
+                    cj/mu4e-attachment-selection-directory))
+    (insert "RET toggle   a mark all   u unmark all   s save marked   q quit\n\n")
+    (dolist (entry cj/mu4e-attachment-selection-entries)
+      (let* ((part (plist-get entry :part))
+             (mark (if (plist-get entry :selected) "[x]" "[ ]"))
+             (label (plist-get entry :label))
+             (mime-type (or (plist-get part :mime-type) ""))
+             (size (if-let ((bytes (plist-get part :decoded-size-approx)))
+                       (file-size-human-readable bytes)
+                     "")))
+        (insert
+         (propertize
+          (format "%s %-40s %-24s %s\n" mark label mime-type size)
+          'cj/mu4e-attachment-entry entry))))
+    (goto-char (point-min))
+    (forward-line (max 0 (1- point-line)))))
+
+(defun cj/mu4e--attachment-selection-setup (parts directory)
+  "Populate the current selection buffer with attachment PARTS and DIRECTORY."
+  (setq cj/mu4e-attachment-selection-directory directory)
+  (setq cj/mu4e-attachment-selection-entries
+        (mapcar (lambda (candidate)
+                  (list :label (car candidate)
+                        :part (cdr candidate)
+                        :selected nil))
+                (cj/mu4e--attachment-candidates parts)))
+  (cj/mu4e--attachment-selection-render))
+
+(defun cj/mu4e-attachment-selection-toggle ()
+  "Toggle the attachment entry at point."
+  (interactive)
+  (let ((entry (cj/mu4e--attachment-selection-entry-at-point)))
+    (setf (plist-get entry :selected)
+          (not (plist-get entry :selected)))
+    (cj/mu4e--attachment-selection-render)))
+
+(defun cj/mu4e-attachment-selection-mark-all ()
+  "Mark all attachments in the selection buffer."
+  (interactive)
+  (dolist (entry cj/mu4e-attachment-selection-entries)
+    (setf (plist-get entry :selected) t))
+  (cj/mu4e--attachment-selection-render))
+
+(defun cj/mu4e-attachment-selection-unmark-all ()
+  "Unmark all attachments in the selection buffer."
+  (interactive)
+  (dolist (entry cj/mu4e-attachment-selection-entries)
+    (setf (plist-get entry :selected) nil))
+  (cj/mu4e--attachment-selection-render))
+
+(defun cj/mu4e-attachment-selection-save-marked ()
+  "Save marked attachments from the selection buffer."
+  (interactive)
+  (let ((parts (mapcar (lambda (entry) (plist-get entry :part))
+                       (seq-filter (lambda (entry)
+                                     (plist-get entry :selected))
+                                   cj/mu4e-attachment-selection-entries))))
+    (unless parts
+      (user-error "No attachments selected"))
+    (let ((paths (cj/mu4e--save-attachment-parts
+                  parts cj/mu4e-attachment-selection-directory)))
+      (message "Saved %d attachment%s to %s"
+               (length paths)
+               (if (= (length paths) 1) "" "s")
+               cj/mu4e-attachment-selection-directory)
+      paths)))
+
+(defun cj/mu4e--open-attachment-selection-buffer (parts directory)
+  "Open an attachment selection buffer for PARTS and DIRECTORY."
+  (let ((buffer (get-buffer-create "*mu4e attachments*")))
+    (with-current-buffer buffer
+      (cj/mu4e-attachment-selection-mode)
+      (cj/mu4e--attachment-selection-setup parts directory))
+    (pop-to-buffer buffer)))
+
+(defun cj/mu4e-save-some-attachments ()
+  "Prompt for a directory and open a buffer to select attachments to save."
+  (interactive)
+  (let ((parts (cj/mu4e--attachment-parts)))
+    (unless parts
+      (user-error "No attachments for this message"))
+    (let ((directory (cj/mu4e--read-attachment-directory parts)))
+      (cj/mu4e--open-attachment-selection-buffer parts directory))))
+
+(provide 'mu4e-attachments)
+;;; mu4e-attachments.el ends here
diff --git a/tests/test-mail-config.el b/tests/test-mail-config.el
new file mode 100644
index 00000000..d2e2cc0b
--- /dev/null
+++ b/tests/test-mail-config.el
@@ -0,0 +1,24 @@
+;;; test-mail-config.el --- Tests for mail-config keymap wiring -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests that mail-config wires the attachment-save commands (defined in
+;; `mu4e-attachments') into its `cj/email-map' prefix keymap.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'mail-config)
+
+(ert-deftest test-mail-config-email-map-attachment-bindings ()
+  "Normal: the email prefix map routes to the attachment-save commands."
+  (should (eq (lookup-key cj/email-map (kbd "S"))
+              #'cj/mu4e-save-all-attachments))
+  (should (eq (lookup-key cj/email-map (kbd "s"))
+              #'cj/mu4e-save-attachment-here))
+  (should (eq (lookup-key cj/email-map (kbd "m"))
+              #'cj/mu4e-save-some-attachments)))
+
+(provide 'test-mail-config)
+;;; test-mail-config.el ends here
diff --git a/tests/test-mail-config-attachments.el b/tests/test-mu4e-attachments.el
index fae50c9c..86a42916 100644
--- a/tests/test-mail-config-attachments.el
+++ b/tests/test-mu4e-attachments.el
@@ -1,8 +1,8 @@
-;;; test-mail-config-attachments.el --- Tests for mu4e attachment helpers -*- lexical-binding: t; -*-
+;;; test-mu4e-attachments.el --- Tests for mu4e attachment helpers -*- lexical-binding: t; -*-
 
 ;;; Commentary:
-;; Tests project-owned attachment save helpers without requiring a live mu4e
-;; view buffer or real MIME handles.
+;; Tests the project-owned attachment save helpers in `mu4e-attachments'
+;; without requiring a live mu4e view buffer or real MIME handles.
 
 ;;; Code:
 
@@ -10,11 +10,11 @@
 (require 'cl-lib)
 
 (add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
-(require 'mail-config)
+(require 'mu4e-attachments)
 
 (defvar mu4e-uniquify-save-file-name-function)
 
-(defun test-mail-config-attachment--part (filename index &optional handle)
+(defun test-mu4e-attachments--part (filename index &optional handle)
   "Return a fake attachment part for FILENAME at INDEX."
   (list :filename filename
         :part-index index
@@ -23,9 +23,9 @@
         :attachment-like t
         :handle (or handle (format "handle-%s" index))))
 
-(ert-deftest test-mail-config-attachments-filters-attachment-like-parts ()
-  "Only attachment-like MIME parts should be saved by the custom commands."
-  (let ((parts (list (test-mail-config-attachment--part "invoice.pdf" 1)
+(ert-deftest test-mu4e-attachments-filters-attachment-like-parts ()
+  "Normal: only attachment-like MIME parts are returned for saving."
+  (let ((parts (list (test-mu4e-attachments--part "invoice.pdf" 1)
                      (list :filename "inline.png"
                            :part-index 2
                            :attachment-like nil
@@ -34,27 +34,27 @@
                            (cj/mu4e--attachment-parts parts))
                    '("invoice.pdf")))))
 
-(ert-deftest test-mail-config-attachments-candidates-disambiguate-duplicates ()
-  "Duplicate filenames should remain individually selectable."
-  (let* ((a (test-mail-config-attachment--part "report.pdf" 1))
-         (b (test-mail-config-attachment--part "report.pdf" 2))
+(ert-deftest test-mu4e-attachments-candidates-disambiguate-duplicates ()
+  "Boundary: duplicate filenames remain individually selectable."
+  (let* ((a (test-mu4e-attachments--part "report.pdf" 1))
+         (b (test-mu4e-attachments--part "report.pdf" 2))
          (candidates (cj/mu4e--attachment-candidates (list a b))))
     (should (equal (mapcar #'car candidates)
                    '("report.pdf <part 1>" "report.pdf <part 2>")))
     (should (eq (cdr (assoc "report.pdf <part 1>" candidates)) a))
     (should (eq (cdr (assoc "report.pdf <part 2>" candidates)) b))))
 
-(ert-deftest test-mail-config-attachments-candidates-keep-unique-names-simple ()
-  "Unique filenames should be shown without extra part-index labels."
-  (let* ((a (test-mail-config-attachment--part "invoice.pdf" 1))
-         (b (test-mail-config-attachment--part "receipt.pdf" 2))
+(ert-deftest test-mu4e-attachments-candidates-keep-unique-names-simple ()
+  "Normal: unique filenames are shown without extra part-index labels."
+  (let* ((a (test-mu4e-attachments--part "invoice.pdf" 1))
+         (b (test-mu4e-attachments--part "receipt.pdf" 2))
          (candidates (cj/mu4e--attachment-candidates (list a b))))
     (should (equal (mapcar #'car candidates)
                    '("invoice.pdf" "receipt.pdf")))))
 
-(ert-deftest test-mail-config-attachments-save-part-uses-mu4e-save-path ()
-  "Saving a part should use mu4e path joining, uniquifying, and MIME saving."
-  (let ((part (test-mail-config-attachment--part "invoice.pdf" 3 "handle"))
+(ert-deftest test-mu4e-attachments-save-part-uses-mu4e-save-path ()
+  "Normal: saving a part uses mu4e path joining, uniquifying, and MIME saving."
+  (let ((part (test-mu4e-attachments--part "invoice.pdf" 3 "handle"))
         (mu4e-uniquify-save-file-name-function
          (lambda (path) (concat path ".unique")))
         saved)
@@ -66,17 +66,19 @@
                      "/downloads/invoice.pdf.unique"))
       (should (equal saved '("handle" "/downloads/invoice.pdf.unique"))))))
 
-(ert-deftest test-mail-config-attachments-save-part-errors-without-handle ()
-  "A malformed part without a MIME handle should fail clearly."
-  (let ((part (test-mail-config-attachment--part "invoice.pdf" 3 nil)))
+(ert-deftest test-mu4e-attachments-save-part-errors-without-handle ()
+  "Error: a malformed part without a MIME handle fails clearly."
+  (let ((part (test-mu4e-attachments--part "invoice.pdf" 3 nil))
+        (mu4e-uniquify-save-file-name-function #'identity))
     (setq part (plist-put part :handle nil))
-    (should-error (cj/mu4e--save-attachment-part part "/downloads")
-                  :type 'user-error)))
-
-(ert-deftest test-mail-config-attachments-save-all-prompts-once ()
-  "The save-all command should prompt for a directory once and save all parts."
-  (let ((parts (list (test-mail-config-attachment--part "a.pdf" 1)
-                     (test-mail-config-attachment--part "b.pdf" 2)))
+    (cl-letf (((symbol-function 'mu4e-join-paths) #'list))
+      (should-error (cj/mu4e--save-attachment-part part "/downloads")
+                    :type 'user-error))))
+
+(ert-deftest test-mu4e-attachments-save-all-prompts-once ()
+  "Normal: the save-all command prompts for a directory once and saves all parts."
+  (let ((parts (list (test-mu4e-attachments--part "a.pdf" 1)
+                     (test-mu4e-attachments--part "b.pdf" 2)))
         saved
         prompts)
     (cl-letf (((symbol-function 'mu4e-view-mime-parts)
@@ -95,10 +97,10 @@
       (should (= 1 (length prompts)))
       (should (equal saved (list parts "/downloads/"))))))
 
-(ert-deftest test-mail-config-attachments-save-selected-prompts-and-selects-one ()
-  "The selected-attachment command should complete by label and save one part."
-  (let* ((a (test-mail-config-attachment--part "a.pdf" 1))
-         (b (test-mail-config-attachment--part "b.pdf" 2))
+(ert-deftest test-mu4e-attachments-save-selected-prompts-and-selects-one ()
+  "Normal: the selected-attachment command completes by label and saves one part."
+  (let* ((a (test-mu4e-attachments--part "a.pdf" 1))
+         (b (test-mu4e-attachments--part "b.pdf" 2))
          (parts (list a b))
          saved)
     (cl-letf (((symbol-function 'mu4e-view-mime-parts)
@@ -118,18 +120,11 @@
       (should (equal (cj/mu4e-save-attachment-here) "/downloads/b.pdf"))
       (should (equal saved (list b "/downloads/"))))))
 
-(ert-deftest test-mail-config-attachments-email-map-bindings ()
-  "Attachment save commands should be available from the email prefix map."
-  (should (eq (lookup-key cj/email-map (kbd "S"))
-              #'cj/mu4e-save-all-attachments))
-  (should (eq (lookup-key cj/email-map (kbd "s"))
-              #'cj/mu4e-save-attachment-here)))
-
-(ert-deftest test-mail-config-attachments-selection-buffer-renders-parts ()
-  "Opening the selection buffer should render attachment rows with metadata."
-  (let* ((a (test-mail-config-attachment--part "a.pdf" 1))
-         (b (test-mail-config-attachment--part "b.pdf" 2))
-         (buffer (get-buffer-create "*test-mail-attachments*")))
+(ert-deftest test-mu4e-attachments-selection-buffer-renders-parts ()
+  "Normal: opening the selection buffer renders attachment rows with metadata."
+  (let* ((a (test-mu4e-attachments--part "a.pdf" 1))
+         (b (test-mu4e-attachments--part "b.pdf" 2))
+         (buffer (get-buffer-create "*test-mu4e-attachments*")))
     (unwind-protect
         (with-current-buffer buffer
           (cj/mu4e-attachment-selection-mode)
@@ -144,10 +139,10 @@
           (should (string-match-p "application/pdf" (buffer-string))))
       (kill-buffer buffer))))
 
-(ert-deftest test-mail-config-attachments-selection-toggle-current-row ()
-  "RET should toggle the selected state for the attachment at point."
-  (let* ((a (test-mail-config-attachment--part "a.pdf" 1))
-         (buffer (get-buffer-create "*test-mail-attachments*")))
+(ert-deftest test-mu4e-attachments-selection-toggle-current-row ()
+  "Normal: RET toggles the selected state for the attachment at point."
+  (let* ((a (test-mu4e-attachments--part "a.pdf" 1))
+         (buffer (get-buffer-create "*test-mu4e-attachments*")))
     (unwind-protect
         (with-current-buffer buffer
           (cj/mu4e-attachment-selection-mode)
@@ -162,11 +157,11 @@
           (should (string-match-p "\\[ \\] a\\.pdf" (buffer-string))))
       (kill-buffer buffer))))
 
-(ert-deftest test-mail-config-attachments-selection-mark-all-and-unmark-all ()
-  "Selection buffer should support marking and unmarking all rows."
-  (let ((parts (list (test-mail-config-attachment--part "a.pdf" 1)
-                     (test-mail-config-attachment--part "b.pdf" 2)))
-        (buffer (get-buffer-create "*test-mail-attachments*")))
+(ert-deftest test-mu4e-attachments-selection-mark-all-and-unmark-all ()
+  "Normal: the selection buffer supports marking and unmarking all rows."
+  (let ((parts (list (test-mu4e-attachments--part "a.pdf" 1)
+                     (test-mu4e-attachments--part "b.pdf" 2)))
+        (buffer (get-buffer-create "*test-mu4e-attachments*")))
     (unwind-protect
         (with-current-buffer buffer
           (cj/mu4e-attachment-selection-mode)
@@ -179,11 +174,11 @@
                                 cj/mu4e-attachment-selection-entries)))
       (kill-buffer buffer))))
 
-(ert-deftest test-mail-config-attachments-selection-save-marked ()
-  "Saving marked rows should save only selected attachment parts."
-  (let* ((a (test-mail-config-attachment--part "a.pdf" 1))
-         (b (test-mail-config-attachment--part "b.pdf" 2))
-         (buffer (get-buffer-create "*test-mail-attachments*"))
+(ert-deftest test-mu4e-attachments-selection-save-marked ()
+  "Normal: saving marked rows saves only the selected attachment parts."
+  (let* ((a (test-mu4e-attachments--part "a.pdf" 1))
+         (b (test-mu4e-attachments--part "b.pdf" 2))
+         (buffer (get-buffer-create "*test-mu4e-attachments*"))
          saved)
     (unwind-protect
         (with-current-buffer buffer
@@ -200,22 +195,22 @@
             (should (equal saved (list (list b) "/downloads/")))))
       (kill-buffer buffer))))
 
-(ert-deftest test-mail-config-attachments-selection-save-marked-errors-when-empty ()
-  "Saving with no marked rows should fail clearly."
-  (let ((buffer (get-buffer-create "*test-mail-attachments*")))
+(ert-deftest test-mu4e-attachments-selection-save-marked-errors-when-empty ()
+  "Error: saving with no marked rows fails clearly."
+  (let ((buffer (get-buffer-create "*test-mu4e-attachments*")))
     (unwind-protect
         (with-current-buffer buffer
           (cj/mu4e-attachment-selection-mode)
           (cj/mu4e--attachment-selection-setup
-           (list (test-mail-config-attachment--part "a.pdf" 1))
+           (list (test-mu4e-attachments--part "a.pdf" 1))
            "/downloads/")
           (should-error (cj/mu4e-attachment-selection-save-marked)
                         :type 'user-error))
       (kill-buffer buffer))))
 
-(ert-deftest test-mail-config-attachments-save-some-opens-selection-buffer ()
-  "The save-some command should prompt for a directory and open a selector."
-  (let ((parts (list (test-mail-config-attachment--part "a.pdf" 1)))
+(ert-deftest test-mu4e-attachments-save-some-opens-selection-buffer ()
+  "Normal: the save-some command prompts for a directory and opens a selector."
+  (let ((parts (list (test-mu4e-attachments--part "a.pdf" 1)))
         opened)
     (cl-letf (((symbol-function 'mu4e-view-mime-parts)
                (lambda () parts))
@@ -228,27 +223,22 @@
       (should (eq (cj/mu4e-save-some-attachments) :buffer))
       (should (equal opened (list parts "/downloads/"))))))
 
-(ert-deftest test-mail-config-attachments-email-map-save-some-binding ()
-  "The email prefix map should include a save-some binding."
-  (should (eq (lookup-key cj/email-map (kbd "m"))
-              #'cj/mu4e-save-some-attachments)))
-
-(ert-deftest test-mail-config-attachments-default-directory-uses-target-dir ()
+(ert-deftest test-mu4e-attachments-default-directory-uses-target-dir ()
   "Normal: the default save directory comes from the part's :target-dir."
-  (let ((parts (list (test-mail-config-attachment--part "a.pdf" 1))))
+  (let ((parts (list (test-mu4e-attachments--part "a.pdf" 1))))
     (should (equal (cj/mu4e--attachment-default-directory parts)
                    "/tmp/mail-target/"))))
 
-(ert-deftest test-mail-config-attachments-default-directory-falls-back-to-downloads ()
+(ert-deftest test-mu4e-attachments-default-directory-falls-back-to-downloads ()
   "Boundary: with no :target-dir hint, the default is ~/Downloads/."
   (let ((parts (list (list :filename "a.pdf" :part-index 1 :attachment-like t))))
     (should (equal (cj/mu4e--attachment-default-directory parts)
                    (file-name-as-directory (expand-file-name "~/Downloads/"))))))
 
-(ert-deftest test-mail-config-attachments-selection-entry-at-point-errors-off-row ()
+(ert-deftest test-mu4e-attachments-selection-entry-at-point-errors-off-row ()
   "Error: asking for the attachment at point on a header line fails clearly."
-  (let* ((a (test-mail-config-attachment--part "a.pdf" 1))
-         (buffer (get-buffer-create "*test-mail-attachments*")))
+  (let* ((a (test-mu4e-attachments--part "a.pdf" 1))
+         (buffer (get-buffer-create "*test-mu4e-attachments*")))
     (unwind-protect
         (with-current-buffer buffer
           (cj/mu4e-attachment-selection-mode)
@@ -258,5 +248,5 @@
                         :type 'user-error))
       (kill-buffer buffer))))
 
-(provide 'test-mail-config-attachments)
-;;; test-mail-config-attachments.el ends here
+(provide 'test-mu4e-attachments)
+;;; test-mu4e-attachments.el ends here