Add unit test

Author: iaalm

Lib/test/test_asyncio/test_tasks.py

@@ -1,6 +1,7 @@
 """Tests for tasks.py."""
 
 import collections
+from concurrent.futures import thread
 import contextlib
 import contextvars
 import gc
@@ -3680,6 +3681,18 @@ def task_factory(loop, coro):
         (loop, context), kwargs = callback.call_args
         self.assertEqual(context['exception'], exc_context.exception)
 
+    def test_run_coroutine_threadsafe_and_cancel(self):
+        async def target():
+            # self.loop.run_in_executor(None, _in_another_thread)
+            thread_future = asyncio.run_coroutine_threadsafe(self.add(1, 2), self.loop)
+            await asyncio.sleep(0)
+
+            thread_future.cancel()
+            await asyncio.sleep(0)
+        
+        self.loop.run_until_complete(target())
+        self.assertEqual(0, len(self.loop._ready))
+
 
 class SleepTests(test_utils.TestCase):
     def setUp(self):