Handle classes/ids after pseudo-classes

tests/test_parser.py

@@ -424,6 +424,14 @@ def test_parse_not_with_missing_argument() -> None:
         _ = NotPseudoClassSelector.from_pseudo_cls(pseudo)
 
 
+def test_parse_class_after_pseudo_class() -> None:
+    tokens = TokenStream([Token(TokenType.PSEUDO_CLASS, ":first-child"), Token(TokenType.CLASS, ".bar")])
+    sel = parse_tokens(tokens)
+    assert isinstance(sel, NthChildPseudoClassSelector)
+    assert isinstance(sel.selector, SimpleSelector)
+    assert sel.selector.classes == ["bar"]
+
+
 def test_parse_multiple_combinators() -> None:
     # div .parent > .child + .sibling:not(.bar):first-child
     tokens = TokenStream(