PR#3535: CLI edit-channel set default value for None and error msg to stderr.

Merges #3535
https://pagure.io/koji/pull-request/3535

Fixes: #3534
https://pagure.io/koji/issue/3534
CLI edit-channel prints error message to stdout

cli/koji_cli/commands.py

@@ -348,6 +348,7 @@ def handle_edit_channel(goptions, session, args):
     cinfo = session.getChannel(args[0])
     if not cinfo:
         error("No such channel: %s" % args[0])
+    result = None
     try:
         result = session.editChannel(args[0], **vals)
     except koji.GenericError as ex:
@@ -357,7 +358,7 @@ def handle_edit_channel(goptions, session, args):
             error("editChannel is available on hub from Koji 1.26 version, your version is %s" %
                   version)
         else:
-            print(msg)
+            warn(msg)
     if not result:
         error("No changes made, please correct the command line")
 

tests/test_cli/test_edit_channel.py

@@ -133,6 +133,29 @@ Options:
         self.session.getChannel.assert_called_once_with(self.channel_old)
         self.session.getKojiVersion.assert_not_called()
 
+    def test_handle_edit_channel_other_error_message(self):
+        expected_api = "Other error message"
+        expected = """Other error message
+No changes made, please correct the command line
+"""
+
+        self.session.editChannel.side_effect = koji.GenericError(expected_api)
+        self.assert_system_exit(
+            handle_edit_channel,
+            self.options,
+            self.session,
+            [self.channel_old, '--name', self.channel_new, '--description', self.description],
+            stderr=expected,
+            stdout='',
+            activate_session=None,
+            exit_code=1
+        )
+        self.session.editChannel.assert_called_once_with(self.channel_old, name=self.channel_new,
+                                                         description=self.description)
+        self.activate_session_mock.assert_called_once_with(self.session, self.options)
+        self.session.getChannel.assert_called_once_with(self.channel_old)
+        self.session.getKojiVersion.assert_not_called()
+
 
 if __name__ == '__main__':
     unittest.main()