Fixed #36712 -- Evaluated type annotations lazily in template tag registration.

Ideally, this will be reverted when an upstream solution is available for
https://github.com/python/cpython/issues/141560.

Thanks Patrick Rauscher for the report and Augusto Pontes for the
first iteration and test.

2 files changed, 43 insertions, 0 deletions

diff --git a/tests/template_tests/test_library.py b/tests/template_tests/test_library.py
index 5827d33223..609b919923 100644
--- a/tests/template_tests/test_library.py
+++ b/tests/template_tests/test_library.py
@@ -1,8 +1,10 @@
 import functools
+import unittest
 
 from django.template import Library
 from django.template.base import Node
 from django.test import SimpleTestCase
+from django.utils.version import PY314
 
 
 class FilterRegistrationTests(SimpleTestCase):
@@ -78,6 +80,14 @@ class InclusionTagRegistrationTests(SimpleTestCase):
         self.assertIs(func_wrapped, func)
         self.assertTrue(hasattr(func_wrapped, "cache_info"))
 
+    @unittest.skipUnless(PY314, "Deferred annotations are Python 3.14+ only")
+    def test_inclusion_tag_deferred_annotation(self):
+        @self.library.inclusion_tag("template.html")
+        def func(arg: SomeType):  # NOQA: F821
+            return ""
+
+        self.assertIn("func", self.library.tags)
+
 
 class SimpleTagRegistrationTests(SimpleTestCase):
     def setUp(self):
@@ -104,6 +114,14 @@ class SimpleTagRegistrationTests(SimpleTestCase):
 
         self.assertIn("name", self.library.tags)
 
+    @unittest.skipUnless(PY314, "Deferred annotations are Python 3.14+ only")
+    def test_tag_deferred_annotation(self):
+        @self.library.simple_tag
+        def func(parser, token: SomeType):  # NOQA: F821
+            return Node()
+
+        self.assertIn("func", self.library.tags)
+
     def test_simple_tag_invalid(self):
         msg = "Invalid arguments provided to simple_tag"
         with self.assertRaisesMessage(ValueError, msg):
@@ -145,6 +163,14 @@ class SimpleBlockTagRegistrationTests(SimpleTestCase):
 
         self.assertIn("name", self.library.tags)
 
+    @unittest.skipUnless(PY314, "Deferred annotations are Python 3.14+ only")
+    def test_simple_block_tag_deferred_annotation(self):
+        @self.library.simple_block_tag
+        def func(content: SomeType):  # NOQA: F821
+            return content
+
+        self.assertIn("func", self.library.tags)
+
     def test_simple_block_tag_invalid(self):
         msg = "Invalid arguments provided to simple_block_tag"
         with self.assertRaisesMessage(ValueError, msg):
diff --git a/tests/template_tests/test_parser.py b/tests/template_tests/test_parser.py
index 317fb88238..9d68955b54 100644
--- a/tests/template_tests/test_parser.py
+++ b/tests/template_tests/test_parser.py
@@ -3,6 +3,8 @@ Testing some internals of the template processing.
 These are *not* examples to be copied in user code.
 """
 
+import unittest
+
 from django.template import Library, TemplateSyntaxError
 from django.template.base import (
     FilterExpression,
@@ -15,6 +17,7 @@ from django.template.base import (
 )
 from django.template.defaultfilters import register as filter_library
 from django.test import SimpleTestCase
+from django.utils.version import PY314
 
 
 class ParserTests(SimpleTestCase):
@@ -240,3 +243,17 @@ class ParserTests(SimpleTestCase):
                     FilterExpression(num, p).resolve({})
                 with self.assertRaises(TemplateSyntaxError):
                     FilterExpression(f"0|default:{num}", p).resolve({})
+
+    @unittest.skipUnless(PY314, "Deferred annotations are Python 3.14+ only")
+    def test_filter_deferred_annotation(self):
+        register = Library()
+
+        @register.filter("example")
+        def example_filter(value: str, arg: SomeType):  # NOQA: F821
+            return f"{value}_{arg}"
+
+        result = FilterExpression.args_check(
+            "example", example_filter, ["extra_example"]
+        )
+
+        self.assertIs(result, True)