irc: default CHANMODES for the mode parser

sopel/irc/modes.py

@@ -116,9 +116,17 @@ class ModeParser:
     }
     """Set of user privileges used by default."""
 
+    CHANMODES = {
+        'A': tuple('beI'),
+        'B': tuple('k'),
+        'C': tuple('l'),
+        'D': tuple('Oaimnqpsrt'),
+    }
+    """Default CHANMODES per :rfc:`2811`."""
+
     def __init__(
         self,
-        chanmodes: Dict[str, Tuple[str, ...]],
+        chanmodes: Dict[str, Tuple[str, ...]] = CHANMODES,
         type_params: Dict[str, ParamRequired] = DEFAULT_MODETYPE_PARAM_CONFIG,
         privileges: Set[str] = PRIVILEGES,
     ) -> None:

test/irc/test_irc_modes.py

@@ -174,6 +174,33 @@ def test_modemessage_get_mode_info_custom_privileges():
         modemessage.get_mode_info('v', REMOVED)
 
 
+def test_modemessage_parse_modestring_default():
+    modeparser = ModeParser()
+    result = modeparser.parse_modestring(
+        '+Oaimn-qpsrt+lk-beI' + '+Z',
+        tuple('abcdef'))
+    assert result.modes == (
+        ('D', 'O', ADDED, None),
+        ('D', 'a', ADDED, None),
+        ('D', 'i', ADDED, None),
+        ('D', 'm', ADDED, None),
+        ('D', 'n', ADDED, None),
+        ('D', 'q', REMOVED, None),
+        ('D', 'p', REMOVED, None),
+        ('D', 's', REMOVED, None),
+        ('D', 'r', REMOVED, None),
+        ('D', 't', REMOVED, None),
+        ('C', 'l', ADDED, 'a'),
+        ('B', 'k', ADDED, 'b'),
+        ('A', 'b', REMOVED, 'c'),
+        ('A', 'e', REMOVED, 'd'),
+        ('A', 'I', REMOVED, 'e'),
+    )
+    assert result.ignored_modes == (('Z', ADDED),)
+    assert not result.privileges
+    assert result.leftover_params == ('f',)
+
+
 def test_modemessage_parse_modestring_single_mode():
     modemessage = ModeParser({
         'X': tuple('bc'),