+test_begin_subtest "notmuch-show: collapse all messages in thread"
+test_emacs '(notmuch-show "id:f35dbb950911171435ieecd458o853c873e35f4be95@mail.gmail.com")
+ (let ((current-prefix-arg t))
+ (notmuch-show-open-or-close-all)
+ (test-visible-output))'
+test_expect_equal_file OUTPUT $EXPECTED/notmuch-show-thread-with-all-messages-collapsed
+
+test_begin_subtest "notmuch-show: uncollapse all messages in thread"
+test_emacs '(notmuch-show "id:f35dbb950911171435ieecd458o853c873e35f4be95@mail.gmail.com")
+ (notmuch-show-open-or-close-all)
+ (test-visible-output)'
+test_expect_equal_file OUTPUT $EXPECTED/notmuch-show-thread-with-all-messages-uncollapsed
+