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.

1 files changed, 252 insertions, 0 deletions

diff --git a/tests/test-mu4e-attachments.el b/tests/test-mu4e-attachments.el
new file mode 100644
index 00000000..86a42916
--- /dev/null
+++ b/tests/test-mu4e-attachments.el
@@ -0,0 +1,252 @@
+;;; test-mu4e-attachments.el --- Tests for mu4e attachment helpers -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests the project-owned attachment save helpers in `mu4e-attachments'
+;; without requiring a live mu4e view buffer or real MIME handles.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'mu4e-attachments)
+
+(defvar mu4e-uniquify-save-file-name-function)
+
+(defun test-mu4e-attachments--part (filename index &optional handle)
+  "Return a fake attachment part for FILENAME at INDEX."
+  (list :filename filename
+        :part-index index
+        :mime-type "application/pdf"
+        :target-dir "/tmp/mail-target"
+        :attachment-like t
+        :handle (or handle (format "handle-%s" index))))
+
+(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
+                           :handle "inline"))))
+    (should (equal (mapcar (lambda (part) (plist-get part :filename))
+                           (cj/mu4e--attachment-parts parts))
+                   '("invoice.pdf")))))
+
+(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-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-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)
+    (cl-letf (((symbol-function 'mu4e-join-paths)
+               (lambda (&rest pieces) (mapconcat #'identity pieces "/")))
+              ((symbol-function 'mm-save-part-to-file)
+               (lambda (handle path) (setq saved (list handle path)))))
+      (should (equal (cj/mu4e--save-attachment-part part "/downloads")
+                     "/downloads/invoice.pdf.unique"))
+      (should (equal saved '("handle" "/downloads/invoice.pdf.unique"))))))
+
+(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))
+    (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)
+               (lambda () parts))
+              ((symbol-function 'read-directory-name)
+               (lambda (prompt &rest _)
+                 (push prompt prompts)
+                 "/downloads/"))
+              ((symbol-function 'cj/mu4e--save-attachment-parts)
+               (lambda (selected directory)
+                 (setq saved (list selected directory))
+                 '("/downloads/a.pdf" "/downloads/b.pdf")))
+              ((symbol-function 'message) (lambda (&rest _) nil)))
+      (should (equal (cj/mu4e-save-all-attachments)
+                     '("/downloads/a.pdf" "/downloads/b.pdf")))
+      (should (= 1 (length prompts)))
+      (should (equal saved (list parts "/downloads/"))))))
+
+(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)
+               (lambda () parts))
+              ((symbol-function 'read-directory-name)
+               (lambda (&rest _) "/downloads/"))
+              ((symbol-function 'completing-read)
+               (lambda (_prompt candidates &rest _)
+                 (should (equal (mapcar #'car candidates)
+                                '("a.pdf" "b.pdf")))
+                 "b.pdf"))
+              ((symbol-function 'cj/mu4e--save-attachment-part)
+               (lambda (part directory)
+                 (setq saved (list part directory))
+                 "/downloads/b.pdf"))
+              ((symbol-function 'message) (lambda (&rest _) nil)))
+      (should (equal (cj/mu4e-save-attachment-here) "/downloads/b.pdf"))
+      (should (equal saved (list b "/downloads/"))))))
+
+(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)
+          (cj/mu4e--attachment-selection-setup (list a b) "/downloads/")
+          (should (eq major-mode 'cj/mu4e-attachment-selection-mode))
+          (should (equal cj/mu4e-attachment-selection-directory "/downloads/"))
+          (should (equal (mapcar (lambda (entry)
+                                   (plist-get entry :label))
+                                 cj/mu4e-attachment-selection-entries)
+                         '("a.pdf" "b.pdf")))
+          (should (string-match-p "\\[ \\] a\\.pdf" (buffer-string)))
+          (should (string-match-p "application/pdf" (buffer-string))))
+      (kill-buffer buffer))))
+
+(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)
+          (cj/mu4e--attachment-selection-setup (list a) "/downloads/")
+          (goto-char (point-min))
+          (search-forward "a.pdf")
+          (cj/mu4e-attachment-selection-toggle)
+          (should (plist-get (car cj/mu4e-attachment-selection-entries) :selected))
+          (should (string-match-p "\\[x\\] a\\.pdf" (buffer-string)))
+          (cj/mu4e-attachment-selection-toggle)
+          (should-not (plist-get (car cj/mu4e-attachment-selection-entries) :selected))
+          (should (string-match-p "\\[ \\] a\\.pdf" (buffer-string))))
+      (kill-buffer buffer))))
+
+(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)
+          (cj/mu4e--attachment-selection-setup parts "/downloads/")
+          (cj/mu4e-attachment-selection-mark-all)
+          (should (seq-every-p (lambda (entry) (plist-get entry :selected))
+                               cj/mu4e-attachment-selection-entries))
+          (cj/mu4e-attachment-selection-unmark-all)
+          (should-not (seq-some (lambda (entry) (plist-get entry :selected))
+                                cj/mu4e-attachment-selection-entries)))
+      (kill-buffer buffer))))
+
+(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
+          (cj/mu4e-attachment-selection-mode)
+          (cj/mu4e--attachment-selection-setup (list a b) "/downloads/")
+          (setf (plist-get (cadr cj/mu4e-attachment-selection-entries) :selected) t)
+          (cl-letf (((symbol-function 'cj/mu4e--save-attachment-parts)
+                     (lambda (parts directory)
+                       (setq saved (list parts directory))
+                       '("/downloads/b.pdf")))
+                    ((symbol-function 'message) (lambda (&rest _) nil)))
+            (should (equal (cj/mu4e-attachment-selection-save-marked)
+                           '("/downloads/b.pdf")))
+            (should (equal saved (list (list b) "/downloads/")))))
+      (kill-buffer buffer))))
+
+(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-mu4e-attachments--part "a.pdf" 1))
+           "/downloads/")
+          (should-error (cj/mu4e-attachment-selection-save-marked)
+                        :type 'user-error))
+      (kill-buffer buffer))))
+
+(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))
+              ((symbol-function 'read-directory-name)
+               (lambda (&rest _) "/downloads/"))
+              ((symbol-function 'cj/mu4e--open-attachment-selection-buffer)
+               (lambda (selected directory)
+                 (setq opened (list selected directory))
+                 :buffer)))
+      (should (eq (cj/mu4e-save-some-attachments) :buffer))
+      (should (equal opened (list parts "/downloads/"))))))
+
+(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-mu4e-attachments--part "a.pdf" 1))))
+    (should (equal (cj/mu4e--attachment-default-directory parts)
+                   "/tmp/mail-target/"))))
+
+(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-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-mu4e-attachments--part "a.pdf" 1))
+         (buffer (get-buffer-create "*test-mu4e-attachments*")))
+    (unwind-protect
+        (with-current-buffer buffer
+          (cj/mu4e-attachment-selection-mode)
+          (cj/mu4e--attachment-selection-setup (list a) "/downloads/")
+          (goto-char (point-min))      ; first line is the "Save attachments to:" header
+          (should-error (cj/mu4e--attachment-selection-entry-at-point)
+                        :type 'user-error))
+      (kill-buffer buffer))))
+
+(provide 'test-mu4e-attachments)
+;;; test-mu4e-attachments.el ends here