coretasks, test: support CHGHOST command/capability

sopel/coretasks.py

@@ -916,6 +916,7 @@ def receive_cap_ls_reply(bot, trigger):
         'echo-message',
         'multi-prefix',
         'away-notify',
+        'chghost',
         'cap-notify',
         'server-time',
     ]
@@ -1239,6 +1240,32 @@ def blocks(bot, trigger):
         bot.reply(STRINGS['huh'])
 
 
+@plugin.event('CHGHOST')
+@plugin.thread(False)
+@plugin.unblockable
+@plugin.priority('medium')
+def recv_chghost(bot, trigger):
+    """Track user/host changes."""
+    if trigger.nick not in bot.users:
+        bot.users[trigger.nick] = target.User(
+            trigger.nick, trigger.user, trigger.host)
+
+    try:
+        new_user, new_host = trigger.args
+    except ValueError:
+        LOGGER.warning(
+            "Ignoring CHGHOST command with %s arguments: %r",
+            'extra' if len(trigger.args) > 2 else 'insufficient',
+            trigger.args)
+        return
+
+    bot.users[trigger.nick].user = new_user
+    bot.users[trigger.nick].host = new_host
+    LOGGER.info(
+        "Update user@host for nick %r: %s@%s",
+        trigger.nick, new_user, new_host)
+
+
 @module.event('ACCOUNT')
 @plugin.thread(False)
 @plugin.unblockable

test/test_coretasks.py

@@ -73,7 +73,7 @@ def test_bot_mixed_mode_removal(mockbot, ircfactory):
     irc.mode_set('#test', '-o+o-qa+v', [
         'Uvoice', 'Uop', 'Uvoice', 'Uvoice', 'Uvoice'])
     assert mockbot.channels["#test"].privileges[Identifier("Uop")] == OP, (
-        'OP got +o only')
+        'Uop got +o only')
     assert mockbot.channels["#test"].privileges[Identifier("Uvoice")] == VOICE, (
         'Uvoice got -o, -q, -a, then +v')
 
@@ -382,3 +382,49 @@ def test_sasl_plain_token_generation():
     assert (
         coretasks._make_sasl_plain_token('sopel', 'sasliscool') ==
         'sopel\x00sopel\x00sasliscool')
+
+
+def test_recv_chghost(mockbot, ircfactory):
+    """Ensure that CHGHOST messages are correctly handled."""
+    irc = ircfactory(mockbot)
+    irc.channel_joined("#test", ["Alex", "Bob", "Cheryl"])
+
+    mockbot.on_message(":[email protected] CHGHOST alex identd.confirmed")
+
+    assert mockbot.users[Identifier('Alex')].user == 'alex'
+    assert mockbot.users[Identifier('Alex')].host == 'identd.confirmed'
+
+
+def test_recv_chghost_invalid(mockbot, ircfactory, caplog):
+    """Ensure that malformed CHGHOST messages are ignored and logged."""
+    irc = ircfactory(mockbot)
+    irc.channel_joined("#test", ["Alex", "Bob", "Cheryl"])
+    alex = Identifier('Alex')
+    bob = Identifier('Bob')
+    cheryl = Identifier('Cheryl')
+
+    # Mock bot + mock IRC server doesn't populate these on its own
+    assert mockbot.users[alex].user is None
+    assert mockbot.users[alex].host is None
+    assert mockbot.users[bob].user is None
+    assert mockbot.users[bob].host is None
+    assert mockbot.users[cheryl].user is None
+    assert mockbot.users[cheryl].host is None
+
+    mockbot.on_message(":[email protected] CHGHOST alex is a boss")
+    mockbot.on_message(":[email protected] CHGHOST rarely")
+    mockbot.on_message(":[email protected] CHGHOST")
+
+    # These should be unchanged
+    assert mockbot.users[alex].user is None
+    assert mockbot.users[alex].host is None
+    assert mockbot.users[bob].user is None
+    assert mockbot.users[bob].host is None
+    assert mockbot.users[cheryl].user is None
+    assert mockbot.users[cheryl].host is None
+
+    # Meanwhile, the malformed input should have generated log lines
+    assert len(caplog.messages) == 3
+    assert 'extra arguments' in caplog.messages[0]
+    assert 'insufficient arguments' in caplog.messages[1]
+    assert 'insufficient arguments' in caplog.messages[2]