chore: coverage, autoload fix, and internal cleanup for org-drill

A batch of test-coverage and hardening work, squashed from the test-work branch.

Tests: deduplicated a colliding leitner-capture test name so make test-name loads again. Added SM2 assert-failure cases, the six basic multicloze variant delegations, the three English-side spanish-verb branches, and org-drill-current-scope branch coverage.

Fix: the entry-point commands (org-drill itself, cram-tree, tree, directory, resume, relearn-item, strip-all-data, merge-buffers) carried no autoload cookies, so M-x failed from a fresh install until something pulled the file in. They're autoloaded now.

Perf: org-drill-shuffle was quadratic because it indexed a list with elt on every swap. It runs a linear Fisher-Yates pass over a vector now, and it checks its argument is a list.

Feat: added org-drill-version, a constant plus an interactive command, so a bug reporter doesn't have to open the file header.

Refactor: extracted org-drill--format-tense-mood, shared by the two verb-conjugation presenters that each carried a copy.

Docs: explained the SM8 magic numbers in the simple8 helpers as empirical fits rather than tunable knobs.

1 files changed, 62 insertions, 0 deletions

diff --git a/tests/test-org-drill-multicloze-dispatch.el b/tests/test-org-drill-multicloze-dispatch.el
index e871105..99861c7 100644
--- a/tests/test-org-drill-multicloze-dispatch.el
+++ b/tests/test-org-drill-multicloze-dispatch.el
@@ -138,6 +138,68 @@ piece is guaranteed not to be the first)."
                (args (cdr call)))
           (should (eq -1 (nth 1 args))))))))
 
+;;;; Basic variants — delegation contract
+;;
+;; hide1/hide2/hide-first/hide-last are thin wrappers.  The hiding
+;; mechanics they delegate to (hide-n / hide-nth) are exercised directly
+;; in test-org-drill-multicloze-hiding.el, so re-driving present-and-reveal
+;; here would just re-test those.  What's untested is the wiring: which
+;; delegate each variant calls and with what argument.
+
+(ert-deftest test-multicloze-hide1-delegates-to-hide-n-1 ()
+  "hide1 hides one piece: delegates to hide-n with number-to-hide = 1."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-n)
+                 (lambda (_session n &rest _) (setq recorded n) t)))
+        (org-drill-present-multicloze-hide1 (org-drill-session))
+        (should (eql 1 recorded))))))
+
+(ert-deftest test-multicloze-hide2-delegates-to-hide-n-2 ()
+  "hide2 hides two pieces: delegates to hide-n with number-to-hide = 2."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-n)
+                 (lambda (_session n &rest _) (setq recorded n) t)))
+        (org-drill-present-multicloze-hide2 (org-drill-session))
+        (should (eql 2 recorded))))))
+
+(ert-deftest test-multicloze-hide-first-delegates-to-hide-nth-1 ()
+  "hide-first hides the first piece: delegates to hide-nth with 1."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-nth)
+                 (lambda (_session nth &rest _) (setq recorded nth) t)))
+        (org-drill-present-multicloze-hide-first (org-drill-session))
+        (should (eql 1 recorded))))))
+
+(ert-deftest test-multicloze-hide-last-delegates-to-hide-nth-last ()
+  "hide-last hides the last piece: delegates to hide-nth with -1."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-nth)
+                 (lambda (_session nth &rest _) (setq recorded nth) t)))
+        (org-drill-present-multicloze-hide-last (org-drill-session))
+        (should (eql -1 recorded))))))
+
+(ert-deftest test-multicloze-show1-delegates-to-hide-n-minus-1 ()
+  "show1 reveals one piece (hides the rest): delegates to hide-n with -1."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-n)
+                 (lambda (_session n &rest _) (setq recorded n) t)))
+        (org-drill-present-multicloze-show1 (org-drill-session))
+        (should (eql -1 recorded))))))
+
+(ert-deftest test-multicloze-show2-delegates-to-hide-n-minus-2 ()
+  "show2 reveals two pieces: delegates to hide-n with -2."
+  (with-fresh-drill-entry
+    (let (recorded)
+      (cl-letf (((symbol-function 'org-drill-present-multicloze-hide-n)
+                 (lambda (_session n &rest _) (setq recorded n) t)))
+        (org-drill-present-multicloze-show2 (org-drill-session))
+        (should (eql -2 recorded))))))
+
 (provide 'test-org-drill-multicloze-dispatch)
 
 ;;; test-org-drill-multicloze-dispatch.el ends here