Changed args_check parameters, Created class to verify deferred annotations only in python 3.14+ version

django/template/base.py

@@ -65,6 +65,7 @@ from django.utils.safestring import SafeData, SafeString, mark_safe
 from django.utils.text import get_text_list, smart_split, unescape_string_literal
 from django.utils.timezone import template_localtime
 from django.utils.translation import gettext_lazy, pgettext_lazy
+from django.utils.version import PY314
 
 from .exceptions import TemplateSyntaxError
 
@@ -92,6 +93,9 @@ tag_re = re.compile(r"({%.*?%}|{{.*?}}|{#.*?#})")
 
 logger = logging.getLogger("django.template")
 
+if PY314:
+    import annotationlib
+
 
 class TokenType(Enum):
     TEXT = 0
@@ -825,20 +829,16 @@ class FilterExpression:
         # Check to see if a decorator is providing the real function.
         func = inspect.unwrap(func)
 
-        try:
-            # Using signature first(more modern)
+        if PY314:
+            sig = inspect.signature(func, annotation_format=annotationlib.Format.FORWARDREF)
+        else:
             sig = inspect.signature(func)
-            alen = len(sig.parameters)
+        alen = len(sig.parameters)
 
-            non_default_params = [
-                p for p in sig.parameters.values() if p.default is p.empty
-            ]
-            dlen = alen - len(non_default_params)
-        except (TypeError, ValueError):
-            # If fails, use the old getfullargspec(deprecated)
-            args, _, _, defaults, _, _, _ = inspect.getfullargspec(func)
-            alen = len(args)
-            dlen = len(defaults or [])
+        non_default_params = [
+            p for p in sig.parameters.values() if p.default is p.empty
+        ]
+        dlen = alen - len(non_default_params)
 
         # Not enough OR Too many
         if plen < (alen - dlen) or plen > alen:

tests/template_tests/test_parser.py

@@ -14,7 +14,16 @@ from django.template.base import (
     VariableDoesNotExist,
 )
 from django.template.defaultfilters import register as filter_library
+from django.utils.version import PY314
 from django.test import SimpleTestCase
+from django.template import Library
+from django.utils.html import escape
+
+from typing import TYPE_CHECKING
+import unittest
+
+if TYPE_CHECKING:
+    from django.utils.safestring import SafeText
 
 
 class ParserTests(SimpleTestCase):
@@ -240,3 +249,17 @@ class ParserTests(SimpleTestCase):
                     FilterExpression(num, p).resolve({})
                 with self.assertRaises(TemplateSyntaxError):
                     FilterExpression(f"0|default:{num}", p).resolve({})
+
+
+class FilterExpressionArgsTests(unittest.TestCase):
+    @unittest.skipUnless(PY314, "Deferred annotations area Python 3.14+ only")
+    def test_register_filter_deferred_annotations(self):
+        register = Library()
+
+        @register.filter("example")
+        def example_filter(value: str) -> SafeText:
+            return escape(value)
+
+        result = example_filter("example")
+
+        self.assertTrue(result)