Add async Python callbacks test that runs in separate Python thread

Author: uentity

tests/test_callbacks.py

@@ -1,5 +1,6 @@
 import pytest
 from pybind11_tests import callbacks as m
+from threading import Thread
 
 
 def test_callbacks():
@@ -127,3 +128,9 @@ def gen_f():
     from time import sleep
     sleep(0.5)
     assert sum(res) == sum([x + 3 for x in work])
+
+
+def test_async_async_callbacks():
+    t = Thread(target=test_async_callbacks)
+    t.start()
+    t.join()