test: add ERT tests for spine-books, fix cl-return-from issue

spine.el

@@ -85,9 +85,10 @@ Returns nil for empty or missing properties."
 (defun spine-books ()
   "Return a list of plists, one per top-level headline in `spine-org-file'.
 Returns nil if the file is missing or cannot be parsed."
-  (unless (file-exists-p spine-org-file)
+  (if (not (file-exists-p spine-org-file))
+      (progn
         (message "spine-books: file not found: %s" spine-org-file)
-    (cl-return-from spine-books nil))
+        nil)
     (condition-case err
         (with-temp-buffer
           (insert-file-contents spine-org-file)
@@ -117,7 +118,7 @@ Returns nil if the file is missing or cannot be parsed."
       (error
        (message "spine-books: failed to parse %s: %s"
                 spine-org-file (error-message-string err))
-     nil)))
+       nil))))
 
 (defvar spine-skip-server-start nil
   "When non-nil, do not start the HTTP server.

test/spine-books-test.el

@@ -0,0 +1,83 @@
+;;; spine-books-test.el — ERT tests for spine-books
+
+(require 'ert)
+(require 'cl-lib)
+
+;; Load spine.el without starting the server
+(setq spine-skip-server-start t)
+(setq spine-org-file (expand-file-name "sample-books.org"
+                                       (file-name-directory
+                                        (directory-file-name
+                                         (file-name-directory load-file-name)))))
+(load-file (expand-file-name "../spine.el"
+                             (file-name-directory load-file-name)))
+
+(ert-deftest spine-books-parses-sample ()
+  "spine-books returns correct plists for sample-books.org."
+  (let ((books (spine-books)))
+    (should books)
+    (should (= (length books) 5))))
+
+(ert-deftest spine-books-first-book-has-all-fields ()
+  "Use of Weapons entry has all expected fields."
+  (let* ((books (spine-books))
+         (uow (cl-find "8c1e-uow" books
+                       :key (lambda (b) (plist-get b :id))
+                       :test #'equal)))
+    (should uow)
+    (should (equal (plist-get uow :title) "Use of Weapons"))
+    (should (equal (plist-get uow :status) "READING"))
+    (should (equal (plist-get uow :author) "Iain M. Banks"))
+    (should (equal (plist-get uow :isbn) "978-0316029193"))
+    (should (equal (plist-get uow :cover) "covers/use-of-weapons.jpg"))
+    (should (equal (plist-get uow :format) "audiobook"))
+    (should (equal (plist-get uow :rec_by) "Priya"))
+    (should (equal (plist-get uow :rec_note) "If you liked Player of Games, this one will wreck you"))
+    (should (equal (plist-get uow :tags) '("scifi" "literary")))
+    (should (equal (plist-get uow :notes)
+                   '(("2026-03-02" "The two-track structure is doing something I can't name yet.")
+                     ("2026-03-07" "Zakalwe's competence reads as a wound.")
+                     ("2026-03-09" "The chapter numbering. Oh."))))))
+
+(ert-deftest spine-books-missing-properties-are-nil ()
+  "Piranesi entry has nil for non-present properties."
+  (let* ((books (spine-books))
+         (pir (cl-find "5e8d-pir" books
+                       :key (lambda (b) (plist-get b :id))
+                       :test #'equal)))
+    (should pir)
+    (should (equal (plist-get pir :title) "Piranesi"))
+    (should (equal (plist-get pir :status) "WANT"))
+    (should (equal (plist-get pir :author) "Susanna Clarke"))
+    (should-not (plist-get pir :isbn))
+    (should-not (plist-get pir :cover))
+    (should-not (plist-get pir :format))
+    (should-not (plist-get pir :rec_by))
+    (should-not (plist-get pir :rec_note))
+    (should-not (plist-get pir :notes))))
+
+(ert-deftest spine-books-read-book-has-rating ()
+  "Ancillary Justice has rating 5."
+  (let* ((books (spine-books))
+         (aj (cl-find "3a1b-aj" books
+                      :key (lambda (b) (plist-get b :id))
+                      :test #'equal)))
+    (should aj)
+    (should (equal (plist-get aj :status) "READ"))
+    (should (equal (plist-get aj :rating) "5"))
+    (should (= (length (plist-get aj :notes)) 3))))
+
+(ert-deftest spine-books-empty-file-returns-empty-list ()
+  "Empty Org file returns empty list, not nil."
+  (let* ((tmp-file (make-temp-file "spine-test-" nil ".org"))
+         (spine-org-file tmp-file))
+    (unwind-protect
+        (let ((books (spine-books)))
+          (should (listp books))
+          (should (= (length books) 0)))
+      (delete-file tmp-file))))
+
+(ert-deftest spine-books-missing-file-returns-nil ()
+  "Non-existent file returns nil."
+  (let ((spine-org-file "/tmp/spine-nonexistent-12345.org"))
+    (should-not (spine-books))))