Forbid creating of stream objects outside of asyncio (#13101)

1 files changed, 12 insertions, 0 deletions

diff --git a/Lib/test/test_asyncio/test_subprocess.py b/Lib/test/test_asyncio/test_subprocess.py
index a5bdb8eca51..3908aabf5a1 100644
--- a/Lib/test/test_asyncio/test_subprocess.py
+++ b/Lib/test/test_asyncio/test_subprocess.py
@@ -510,6 +510,18 @@ class SubprocessMixin:
 
         self.loop.run_until_complete(execute())
 
+    def test_subprocess_protocol_create_warning(self):
+        with self.assertWarns(DeprecationWarning):
+            subprocess.SubprocessStreamProtocol(limit=10, loop=self.loop)
+
+    def test_process_create_warning(self):
+        proto = subprocess.SubprocessStreamProtocol(limit=10, loop=self.loop,
+                                                    _asyncio_internal=True)
+        transp = mock.Mock()
+
+        with self.assertWarns(DeprecationWarning):
+            subprocess.Process(transp, proto, loop=self.loop)
+
 
 if sys.platform != 'win32':
     # Unix