test(celery): Test that message ID set on span

tests/integrations/celery/test_celery.py

@@ -616,3 +616,17 @@ def example_task():
         pytest.fail("Calling `apply_async` without arguments raised a TypeError")
 
     assert result.get() == "success"
+
+
+def test_messaging_id(init_celery, capture_events):
+    celery = init_celery(enable_tracing=True)
+    events = capture_events()
+
+    @celery.task
+    def example_task(): ...
+
+    example_task.apply_async()
+
+    (event,) = events
+    (span,) = event["spans"]
+    assert "messaging.message.id" in span["data"]