From 636583d5808eacbdd2eb1a669786ea987fd56d66 Mon Sep 17 00:00:00 2001
From: Friday <aifriday700@gmail.com>
Date: Tue, 17 Feb 2026 12:06:33 +0000
Subject: [PATCH] Fix F821 false positive for aliased Annotated and Literal
 imports

Use _is_typing() in addition to _is_name_or_attr() when checking for
Literal and Annotated subscripts. _is_typing() resolves import aliases
through the scope stack, so `from typing import Annotated as Ann` is
correctly recognized. The _is_name_or_attr() fallback is kept to
preserve the existing false-negative-safe behavior for non-typing
modules that happen to export names called Literal or Annotated.

Closes #789

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 pyflakes/checker.py                    | 10 ++++++++--
 pyflakes/test/test_type_annotations.py | 26 ++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/pyflakes/checker.py b/pyflakes/checker.py
index 629dacf0..71b134a1 100644
--- a/pyflakes/checker.py
+++ b/pyflakes/checker.py
@@ -1372,10 +1372,16 @@ def ignore(self, node):
         NAMEDEXPR = handleChildren
 
     def SUBSCRIPT(self, node):
-        if _is_name_or_attr(node.value, 'Literal'):
+        if (
+            _is_typing(node.value, 'Literal', self.scopeStack)
+            or _is_name_or_attr(node.value, 'Literal')
+        ):
             with self._enter_annotation(AnnotationState.NONE):
                 self.handleChildren(node)
-        elif _is_name_or_attr(node.value, 'Annotated'):
+        elif (
+            _is_typing(node.value, 'Annotated', self.scopeStack)
+            or _is_name_or_attr(node.value, 'Annotated')
+        ):
             self.handleNode(node.value, node)
 
             # py39+
diff --git a/pyflakes/test/test_type_annotations.py b/pyflakes/test/test_type_annotations.py
index f4f8ded5..1979e1bc 100644
--- a/pyflakes/test/test_type_annotations.py
+++ b/pyflakes/test/test_type_annotations.py
@@ -598,6 +598,32 @@ def f(x: Literal['some string', 'foo bar']) -> None:
             return None
         """)
 
+    def test_annotated_type_typing_alias(self):
+        """Annotated imported under an alias should not produce F821."""
+        self.flakes("""
+        from typing_extensions import Annotated as WithSchema
+
+        def f(x: WithSchema[int, 'hello']) -> None:
+            return None
+        """)
+
+    def test_annotated_type_typing_alias_forward_type(self):
+        self.flakes("""
+        from typing import Annotated as Ann
+
+        def f(x: Ann['integer', 1]) -> None:
+            return None
+        """, m.UndefinedName)
+
+    def test_literal_type_typing_alias(self):
+        """Literal imported under an alias should not produce F821."""
+        self.flakes("""
+        from typing import Literal as Lit
+
+        def f(x: Lit['some string']) -> None:
+            return None
+        """)
+
     def test_deferred_twice_annotation(self):
         self.flakes("""
             from queue import Queue