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'.

5 files changed, 103 insertions, 0 deletions

diff --git a/tests/test-calendar-sync-async-worker.el b/tests/test-calendar-sync-async-worker.el
index 6701df85..3bf803ec 100644
--- a/tests/test-calendar-sync-async-worker.el
+++ b/tests/test-calendar-sync-async-worker.el
@@ -37,8 +37,21 @@
                             (string-match-p "'(\"me@example\\.test\")" arg)))
                      command))))
 
+(ert-deftest test-calendar-sync--worker-command-puts-L-before-l ()
+  "Order: `-L module-dir' must precede `-l calendar-sync.el' so the sibling
+load-path entry is in effect by the time the module load runs.  Asserting both
+via `member' separately wouldn't catch a swap."
+  (let* ((calendar-sync--module-file "/tmp/calendar-sync.el")
+         (calendar-sync-past-months 2)
+         (calendar-sync-future-months 6)
+         (calendar-sync-user-emails '("me@example.test"))
+         (command (calendar-sync--worker-command "/tmp/input.ics" "/tmp/output.org")))
+    (should (< (cl-position "-L" command :test #'equal)
+               (cl-position "-l" command :test #'equal)))))
+
 (ert-deftest test-calendar-sync--worker-command-loads-sibling-modules-without-init ()
   "The worker command should load calendar-sync and sibling modules without init."
+  :tags '(:slow)
   (let* ((calendar-sync--module-file
           (expand-file-name "modules/calendar-sync.el" user-emacs-directory))
          (command (append
diff --git a/tests/test-calibredb-epub-config.el b/tests/test-calibredb-epub-config.el
index 5b578b7d..53d2e78f 100644
--- a/tests/test-calibredb-epub-config.el
+++ b/tests/test-calibredb-epub-config.el
@@ -40,6 +40,17 @@
                (lambda (&rest _) nil)))
       (should (= 40 (cj/nov--text-width-for-window))))))
 
+(ert-deftest test-calibredb-epub-nov-text-width-clamps-negative-margin ()
+  "Boundary: a negative margin percent is clamped up to 0, so the text takes
+the full window width."
+  (let ((cj/nov-margin-percent -10)
+        (cj/nov-min-text-width 40))
+    (cl-letf (((symbol-function 'get-buffer-window)
+               (lambda (&rest _) 'window))
+              ((symbol-function 'window-body-width)
+               (lambda (_) 120)))
+      (should (= 120 (cj/nov--text-width-for-window))))))
+
 (ert-deftest test-calibredb-epub-open-external-uses-zathura ()
   "Normal: named Nov external-open command delegates to zathura."
   (let (command)
diff --git a/tests/test-lorem-optimum.el b/tests/test-lorem-optimum.el
index 40bdc684..f928c972 100644
--- a/tests/test-lorem-optimum.el
+++ b/tests/test-lorem-optimum.el
@@ -247,5 +247,11 @@
       (should (> (length result) 0))
       (should (string-match-p "^[[:upper:]]" result)))))
 
+(ert-deftest test-title-generation-empty-chain-returns-empty-string ()
+  "Boundary: an empty Markov chain (`cj/markov-random-key' returns nil) yields
+an empty string, not an error."
+  (let ((cj/lipsum-chain (cj/markov-chain-create)))
+    (should (equal "" (cj/lipsum-title)))))
+
 (provide 'test-lorem-optimum)
 ;;; test-lorem-optimum.el ends here
diff --git a/tests/test-mail-config-attachments.el b/tests/test-mail-config-attachments.el
index eee0ff70..fae50c9c 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
diff --git a/tests/test-org-capture-config-target-cache.el b/tests/test-org-capture-config-target-cache.el
index 7b88975b..f127bfbc 100644
--- a/tests/test-org-capture-config-target-cache.el
+++ b/tests/test-org-capture-config-target-cache.el
@@ -85,5 +85,53 @@ The file-visiting buffer is killed after BODY returns."
             (should (cj/org-capture--headline-marker-valid-p marker "Inbox")))))
     (test-org-capture-target-cache--reset)))
 
+(ert-deftest test-org-capture-target-cache-recovers-after-buffer-killed ()
+  "Boundary: killing the marker's buffer invalidates the cache entry.
+The next capture rescans (and refreshes), without crashing on the stale marker."
+  (test-org-capture-target-cache--reset)
+  (unwind-protect
+      (test-org-capture-target-cache--with-temp-org-file
+          "* Inbox\n"
+        (let ((org-capture-plist `(:target (file+headline ,file "Inbox"))))
+          (org-capture-set-target-location)
+          (let* ((key (cj/org-capture--file-headline-cache-key file "Inbox"))
+                 (marker (gethash key cj/org-capture--file-headline-target-cache)))
+            (kill-buffer (marker-buffer marker))
+            (should-not (cj/org-capture--headline-marker-valid-p marker "Inbox"))
+            ;; A second resolution must succeed without erroring on the stale marker.
+            (org-capture-set-target-location)
+            (let ((fresh (gethash key cj/org-capture--file-headline-target-cache)))
+              (should (cj/org-capture--headline-marker-valid-p fresh "Inbox"))))))
+    (test-org-capture-target-cache--reset)))
+
+(ert-deftest test-org-capture-target-cache-clear-empties-the-hash ()
+  "Normal: `cj/org-capture-clear-target-cache' actually empties the cache."
+  (test-org-capture-target-cache--reset)
+  (unwind-protect
+      (test-org-capture-target-cache--with-temp-org-file
+          "* Inbox\n"
+        (let ((org-capture-plist `(:target (file+headline ,file "Inbox"))))
+          (org-capture-set-target-location)
+          (should (= 1 (hash-table-count cj/org-capture--file-headline-target-cache)))
+          ;; Suppress the user-facing message during the test.
+          (cl-letf (((symbol-function 'message) (lambda (&rest _) nil)))
+            (cj/org-capture-clear-target-cache))
+          (should (= 0 (hash-table-count cj/org-capture--file-headline-target-cache)))))
+    (test-org-capture-target-cache--reset)))
+
+(ert-deftest test-org-capture-target-cache-falls-through-for-non-file+headline ()
+  "Boundary: targets that aren't `file+headline' (e.g. plain `file', `file+olp',
+`file+function') fall through to the original `org-capture-set-target-location'
+unchanged."
+  (test-org-capture-target-cache--reset)
+  (dolist (target '((file "/tmp/fall-through.org")
+                    (file+olp "/tmp/fall-through.org" "Tasks" "Inbox")
+                    (file+function "/tmp/fall-through.org" ignore)))
+    (let ((called-with nil))
+      (cj/org-capture--set-target-location-advice
+       (lambda (&optional received) (setq called-with (list :ran received)))
+       target)
+      (should (equal called-with (list :ran target))))))
+
 (provide 'test-org-capture-config-target-cache)
 ;;; test-org-capture-config-target-cache.el ends here