add a test for confusable nicks

irctest/cases.py

@@ -344,10 +344,10 @@ class BaseServerTestCase(_IrcTestCase):
                             ', '.join(capabilities))
                 else:
                     raise
+            self.sendLine(client, 'CAP END')
         if password is not None:
             self.sendLine(client, 'AUTHENTICATE PLAIN')
             self.sendLine(client, sasl_plain_blob(nick, password))
-            self.sendLine(client, 'CAP END')
         self.sendLine(client, 'NICK {}'.format(nick))
         self.sendLine(client, 'USER username * * :Realname')
 

irctest/server_tests/test_confusables.py

@@ -0,0 +1,32 @@
+from irctest import cases
+from irctest.numerics import RPL_WELCOME, ERR_NICKNAMEINUSE
+
+class ConfusablesTestCase(cases.BaseServerTestCase):
+
+    def customizedConfig(self):
+        config = self.controller.baseConfig()
+        config['accounts']['nick-reservation'] = {
+            'enabled': True,
+            'method': 'strict',
+        }
+        return config
+
+    @cases.SpecificationSelector.requiredBySpecification('Oragono')
+    def testConfusableNicks(self):
+        self.controller.registerUser(self, 'evan', 'sesame')
+
+        self.addClient(1)
+        # U+0435 in place of e:
+        self.sendLine(1, 'NICK еvan')
+        self.sendLine(1, 'USER a 0 * a')
+        messages = self.getMessages(1)
+        commands = set(msg.command for msg in messages)
+        self.assertNotIn(RPL_WELCOME, commands)
+        self.assertIn(ERR_NICKNAMEINUSE, commands)
+
+        self.connectClient('evan', name='evan', password='sesame')
+        # should be able to switch to the confusable nick
+        self.sendLine('evan', 'NICK еvan')
+        messages = self.getMessages('evan')
+        commands = set(msg.command for msg in messages)
+        self.assertIn('NICK', commands)