Fix false positive for ``keyword-arg-before-vararg`` (#8571) (#8578)

* Fix false positive for ``keyword-arg-before-vararg`` when a positional-only parameter with a default value precedes ``*args``.

Closes #8570

(cherry picked from commit 56fa5dce747a46f1dcba6eca003bb22fcc347247)

Co-authored-by: Mark Byrne <31762852+mbyrnepr2@users.noreply.github.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index 0c8c44a15..1a628f231 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -1001,8 +1001,14 @@ accessed. Python regular expressions are accepted.",
 
     @only_required_for_messages("keyword-arg-before-vararg")
     def visit_functiondef(self, node: nodes.FunctionDef) -> None:
-        # check for keyword arg before varargs
+        # check for keyword arg before varargs.
+
         if node.args.vararg and node.args.defaults:
+            # When `positional-only` parameters are present then only
+            # `positional-or-keyword` parameters are checked. I.e:
+            # >>> def name(pos_only_params, /, pos_or_keyword_params, *args): ...
+            if node.args.posonlyargs and not node.args.args:
+                return
             self.add_message("keyword-arg-before-vararg", node=node, args=(node.name))
 
     visit_asyncfunctiondef = visit_functiondef