test the e.errno != socket.EAI_NONAME branch in tcp._getaddrinfo

distributed/comm/tests/test_tcp.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+import socket
+
+import pytest
+
+from distributed.comm.tcp import TCPConnector
+
+
+# cover the `if e.errno != socket.EAI_NONAME` branch of tcp._getaddrinfo
+def test_getaddrinfo_invalid_af():
+    with pytest.raises(socket.gaierror) as exc_info:
+        (
+            TCPConnector()
+            .client.connect(host="::1", port=1234, af=socket.AF_INET)
+            .__await__()
+            # test that getaddrinfo is called without yielding to the event loop
+            .send(None)
+        )
+    assert exc_info.value.errno == socket.EAI_ADDRFAMILY