fix(tests): wait for the sound sentinel, not just the child's exit

process-live-p goes nil the moment the child exits, but its sentinel is queued and runs on a later turn of the event loop. Two sound tests stopped waiting at process death, so the sentinel's message landed inside the next test's message mock.

make coverage caught it. Instrumentation slowed things just enough that "false exited with status 1" showed up in the silent-player test. The plain suite had been passing by luck.

Both tests now wait for the sentinel to have run.

1 files changed, 26 insertions, 5 deletions

diff --git a/tests/test-chime-sound.el b/tests/test-chime-sound.el
index 0160d50..c43231a 100644
--- a/tests/test-chime-sound.el
+++ b/tests/test-chime-sound.el
@@ -68,6 +68,25 @@ in the capture list and a bare count assertion fails.  Assert on what chime
 said, not on Emacs having said nothing."
   (seq-filter (lambda (m) (string-prefix-p "chime:" m)) messages))
 
+(defun test-chime-sound--await-exit (process &optional until)
+  "Wait for PROCESS to exit and for its sentinel to have run.
+UNTIL, when given, is polled after each turn of the event loop; waiting
+stops as soon as it returns non-nil.
+
+`process-live-p' goes nil the moment the child exits, but the sentinel is
+queued and runs on a *later* turn of the event loop.  A test that stops
+waiting at process death therefore lets the sentinel's message land inside
+the next test's `message' mock.  That is not hypothetical: it put \"false
+exited with status 1\" into the silent-player test under a coverage run,
+where instrumentation slowed things just enough to expose the race."
+  (while (process-live-p process)
+    (accept-process-output process 0 50))
+  (let ((deadline (time-add (current-time)
+                            (seconds-to-time (if until 2 0.3)))))
+    (while (and (time-less-p (current-time) deadline)
+                (not (and until (funcall until))))
+      (accept-process-output nil 0 20))))
+
 ;;; Normal Cases
 
 (chime-deftest test-chime-sound-find-sound-player-auto-returns-first-available ()
@@ -241,9 +260,10 @@ synchronous `play-sound-file' path returns t instead."
                (lambda (fmt &rest args) (push (apply #'format fmt args) messages))))
       (let ((process (chime--play-sound)))
         (should (processp process))
-        ;; The sentinel fires when the player exits, not before.
-        (while (process-live-p process)
-          (accept-process-output process 0 50)))
+        ;; The sentinel fires after the player exits, on a later turn of the
+        ;; event loop -- wait for the message, not merely for the exit.
+        (test-chime-sound--await-exit
+         process (lambda () (test-chime-sound--chime-messages messages))))
       (let ((chime-messages (test-chime-sound--chime-messages messages)))
         (should (= (length chime-messages) 1))
         (should (string-match-p "Failed to play sound" (car chime-messages)))
@@ -258,8 +278,9 @@ synchronous `play-sound-file' path returns t instead."
     (cl-letf (((symbol-function 'message)
                (lambda (fmt &rest args) (push (apply #'format fmt args) messages))))
       (let ((process (chime--play-sound)))
-        (while (process-live-p process)
-          (accept-process-output process 0 50)))
+        ;; Drain the sentinel too, so a late message can't slip past the
+        ;; assertion and into the next test.
+        (test-chime-sound--await-exit process))
       (should-not (test-chime-sound--chime-messages messages)))))
 
 (chime-deftest test-chime-sound-both-players-failing-reports-once-and-does-not-signal ()