Improve NoValidConnectionsError formatting

Because "Unable to connect to port 22 on  or X.X.X.X" looks seriously
_weird_ with the blank space between "on" and "or".

1 files changed, 16 insertions, 1 deletions

diff --git a/tests/test_ssh_exception.py b/tests/test_ssh_exception.py
index 2d1f899f..9c109de1 100644
--- a/tests/test_ssh_exception.py
+++ b/tests/test_ssh_exception.py
@@ -8,8 +8,23 @@ class NoValidConnectionsErrorTest (unittest.TestCase):
 
     def test_pickling(self):
         # Regression test for https://github.com/paramiko/paramiko/issues/617
-        exc = NoValidConnectionsError({'ab': ''})
+        exc = NoValidConnectionsError({('127.0.0.1', '22'): Exception()})
         new_exc = pickle.loads(pickle.dumps(exc))
         self.assertEqual(type(exc), type(new_exc))
         self.assertEqual(str(exc), str(new_exc))
         self.assertEqual(exc.args, new_exc.args)
+
+    def test_error_message_for_single_host(self):
+        exc = NoValidConnectionsError({('127.0.0.1', '22'): Exception()})
+        self.assertIn("Unable to connect to port 22 on 127.0.0.1", str(exc))
+
+    def test_error_message_for_two_hosts(self):
+        exc = NoValidConnectionsError({('127.0.0.1', '22'): Exception(),
+                                       ('::1', '22'): Exception()})
+        self.assertIn("Unable to connect to port 22 on 127.0.0.1 or ::1", str(exc))
+
+    def test_error_message_for_multiple_hosts(self):
+        exc = NoValidConnectionsError({('127.0.0.1', '22'): Exception(),
+                                       ('::1', '22'): Exception(),
+                                       ('10.0.0.42', '22'): Exception()})
+        self.assertIn("Unable to connect to port 22 on 10.0.0.42, 127.0.0.1 or ::1", str(exc))