test: close coverage gaps from the preceding batch

Untested paths surfaced while reviewing the preceding feature/fix commits:
- calendar-sync: a test that `-L' precedes `-l' in the worker command (separate `member' checks wouldn't catch a swap), plus a `:slow' tag on the real-subprocess worker test so it stays out of the default `make test' run.
- org-capture cache: a killed marker buffer invalidates the entry and the next resolution rescans without erroring on the stale marker, `cj/org-capture-clear-target-cache' actually empties the hash, and non-`file+headline' targets (`file', `file+olp', `file+function') fall through to the original `org-capture-set-target-location'.
- lorem-optimum: `cj/lipsum-title' on an empty chain returns "", not an error.
- calibredb-epub: a negative `cj/nov-margin-percent' is clamped up to 0 (text takes the full window width).
- mu4e attachments: the default save directory comes from the part's `:target-dir' and falls back to `~/Downloads/', and asking for the attachment at point on a header line fails with a `user-error'.

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/test-mail-config-attachments.el b/tests/test-mail-config-attachments.el
index eee0ff708..fae50c9cc 100644
--- a/tests/test-mail-config-attachments.el
+++ b/tests/test-mail-config-attachments.el
@@ -233,5 +233,30 @@
   (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 ()
+  "Normal: the default save directory comes from the part's :target-dir."
+  (let ((parts (list (test-mail-config-attachment--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 ()
+  "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 ()
+  "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*")))
+    (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-mail-config-attachments)
 ;;; test-mail-config-attachments.el ends here