Fixed #36728 -- Validated template tag arguments at definition time.

Before, `context` and `content` were validated at compile time.

8 files changed, 94 insertions, 159 deletions

diff --git a/django/contrib/admin/templatetags/admin_list.py b/django/contrib/admin/templatetags/admin_list.py
index 2100f93566..52aae9e589 100644
--- a/django/contrib/admin/templatetags/admin_list.py
+++ b/django/contrib/admin/templatetags/admin_list.py
@@ -76,6 +76,7 @@ def pagination(cl):
 @register.tag(name="pagination")
 def pagination_tag(parser, token):
     return InclusionAdminNode(
+        "pagination",
         parser,
         token,
         func=pagination,
@@ -361,6 +362,7 @@ def result_list(cl):
 @register.tag(name="result_list")
 def result_list_tag(parser, token):
     return InclusionAdminNode(
+        "result_list",
         parser,
         token,
         func=result_list,
@@ -481,6 +483,7 @@ def date_hierarchy(cl):
 @register.tag(name="date_hierarchy")
 def date_hierarchy_tag(parser, token):
     return InclusionAdminNode(
+        "date_hierarchy",
         parser,
         token,
         func=date_hierarchy,
@@ -505,6 +508,7 @@ def search_form(cl):
 @register.tag(name="search_form")
 def search_form_tag(parser, token):
     return InclusionAdminNode(
+        "search_form",
         parser,
         token,
         func=search_form,
@@ -537,7 +541,7 @@ def admin_actions(context):
 @register.tag(name="admin_actions")
 def admin_actions_tag(parser, token):
     return InclusionAdminNode(
-        parser, token, func=admin_actions, template_name="actions.html"
+        "admin_actions", parser, token, func=admin_actions, template_name="actions.html"
     )
 
 
@@ -545,6 +549,7 @@ def admin_actions_tag(parser, token):
 def change_list_object_tools_tag(parser, token):
     """Display the row of change list object tools."""
     return InclusionAdminNode(
+        "change_list_object_tools",
         parser,
         token,
         func=lambda context: context,
diff --git a/django/contrib/admin/templatetags/admin_modify.py b/django/contrib/admin/templatetags/admin_modify.py
index 0e3046ae5a..c3d2ad01d9 100644
--- a/django/contrib/admin/templatetags/admin_modify.py
+++ b/django/contrib/admin/templatetags/admin_modify.py
@@ -51,6 +51,7 @@ def prepopulated_fields_js(context):
 @register.tag(name="prepopulated_fields_js")
 def prepopulated_fields_js_tag(parser, token):
     return InclusionAdminNode(
+        "prepopulated_fields_js",
         parser,
         token,
         func=prepopulated_fields_js,
@@ -115,7 +116,7 @@ def submit_row(context):
 @register.tag(name="submit_row")
 def submit_row_tag(parser, token):
     return InclusionAdminNode(
-        parser, token, func=submit_row, template_name="submit_line.html"
+        "submit_row", parser, token, func=submit_row, template_name="submit_line.html"
     )
 
 
@@ -123,6 +124,7 @@ def submit_row_tag(parser, token):
 def change_form_object_tools_tag(parser, token):
     """Display the row of change form object tools."""
     return InclusionAdminNode(
+        "change_form_object_tools",
         parser,
         token,
         func=lambda context: context,
diff --git a/django/contrib/admin/templatetags/base.py b/django/contrib/admin/templatetags/base.py
index 3f8290d3b1..c0474135ea 100644
--- a/django/contrib/admin/templatetags/base.py
+++ b/django/contrib/admin/templatetags/base.py
@@ -1,5 +1,6 @@
 from inspect import getfullargspec
 
+from django.template.exceptions import TemplateSyntaxError
 from django.template.library import InclusionNode, parse_bits
 from django.utils.inspect import lazy_annotations
 
@@ -10,12 +11,21 @@ class InclusionAdminNode(InclusionNode):
     or globally.
     """
 
-    def __init__(self, parser, token, func, template_name, takes_context=True):
+    def __init__(self, name, parser, token, func, template_name, takes_context=True):
         self.template_name = template_name
         with lazy_annotations():
             params, varargs, varkw, defaults, kwonly, kwonly_defaults, _ = (
                 getfullargspec(func)
             )
+        if takes_context:
+            if params and params[0] == "context":
+                del params[0]
+            else:
+                function_name = func.__name__
+                raise TemplateSyntaxError(
+                    f"{name!r} sets takes_context=True so {function_name!r} "
+                    "must have a first argument of 'context'"
+                )
         bits = token.split_contents()
         args, kwargs = parse_bits(
             parser,
@@ -26,7 +36,6 @@ class InclusionAdminNode(InclusionNode):
             defaults,
             kwonly,
             kwonly_defaults,
-            takes_context,
             bits[0],
         )
         super().__init__(func, takes_context, args, kwargs, filename=None)
diff --git a/django/template/library.py b/django/template/library.py
index 27af7a6969..0a459c0497 100644
--- a/django/template/library.py
+++ b/django/template/library.py
@@ -123,6 +123,15 @@ class Library:
                 ) = getfullargspec(unwrap(func))
             function_name = name or func.__name__
 
+            if takes_context:
+                if params and params[0] == "context":
+                    del params[0]
+                else:
+                    raise TemplateSyntaxError(
+                        f"{function_name!r} is decorated with takes_context=True so it "
+                        "must have a first argument of 'context'"
+                    )
+
             @wraps(func)
             def compile_func(parser, token):
                 bits = token.split_contents()[1:]
@@ -139,7 +148,6 @@ class Library:
                     defaults,
                     kwonly,
                     kwonly_defaults,
-                    takes_context,
                     function_name,
                 )
                 return SimpleNode(func, takes_context, args, kwargs, target_var)
@@ -182,26 +190,32 @@ class Library:
             if end_name is None:
                 end_name = f"end{function_name}"
 
-            @wraps(func)
-            def compile_func(parser, token):
-                tag_params = params.copy()
+            if takes_context:
+                if len(params) >= 2 and params[1] == "content":
+                    del params[1]
+                else:
+                    raise TemplateSyntaxError(
+                        f"{function_name!r} is decorated with takes_context=True so"
+                        " it must have a first argument of 'context' and a second "
+                        "argument of 'content'"
+                    )
 
-                if takes_context:
-                    if len(tag_params) >= 2 and tag_params[1] == "content":
-                        del tag_params[1]
-                    else:
-                        raise TemplateSyntaxError(
-                            f"{function_name!r} is decorated with takes_context=True so"
-                            " it must have a first argument of 'context' and a second "
-                            "argument of 'content'"
-                        )
-                elif tag_params and tag_params[0] == "content":
-                    del tag_params[0]
+                if params and params[0] == "context":
+                    del params[0]
                 else:
                     raise TemplateSyntaxError(
-                        f"'{function_name}' must have a first argument of 'content'"
+                        f"{function_name!r} is decorated with takes_context=True so it "
+                        "must have a first argument of 'context'"
                     )
+            elif params and params[0] == "content":
+                del params[0]
+            else:
+                raise TemplateSyntaxError(
+                    f"{function_name!r} must have a first argument of 'content'"
+                )
 
+            @wraps(func)
+            def compile_func(parser, token):
                 bits = token.split_contents()[1:]
                 target_var = None
                 if len(bits) >= 2 and bits[-2] == "as":
@@ -214,13 +228,12 @@ class Library:
                 args, kwargs = parse_bits(
                     parser,
                     bits,
-                    tag_params,
+                    params,
                     varargs,
                     varkw,
                     defaults,
                     kwonly,
                     kwonly_defaults,
-                    takes_context,
                     function_name,
                 )
 
@@ -263,6 +276,15 @@ class Library:
                 ) = getfullargspec(unwrap(func))
             function_name = name or func.__name__
 
+            if takes_context:
+                if params and params[0] == "context":
+                    params = params[1:]
+                else:
+                    raise TemplateSyntaxError(
+                        f"{function_name!r} is decorated with takes_context=True so it "
+                        "must have a first argument of 'context'"
+                    )
+
             @wraps(func)
             def compile_func(parser, token):
                 bits = token.split_contents()[1:]
@@ -275,7 +297,6 @@ class Library:
                     defaults,
                     kwonly,
                     kwonly_defaults,
-                    takes_context,
                     function_name,
                 )
                 return InclusionNode(
@@ -394,7 +415,6 @@ def parse_bits(
     defaults,
     kwonly,
     kwonly_defaults,
-    takes_context,
     name,
 ):
     """
@@ -402,14 +422,6 @@ def parse_bits(
     particular by detecting syntax errors and by extracting positional and
     keyword arguments.
     """
-    if takes_context:
-        if params and params[0] == "context":
-            params = params[1:]
-        else:
-            raise TemplateSyntaxError(
-                "'%s' is decorated with takes_context=True so it must "
-                "have a first argument of 'context'" % name
-            )
     args = []
     kwargs = {}
     unhandled_params = list(params)
diff --git a/tests/admin_views/test_templatetags.py b/tests/admin_views/test_templatetags.py
index e8129cce1d..69bae27412 100644
--- a/tests/admin_views/test_templatetags.py
+++ b/tests/admin_views/test_templatetags.py
@@ -144,6 +144,7 @@ class AdminTemplateTagsTest(AdminViewBasicTestCase):
         # inspect.getfullargspec(), which is not ready for deferred
         # evaluation of annotations.
         InclusionAdminNode(
+            "test",
             parser=object(),
             token=Token(token_type=TokenType.TEXT, contents="a"),
             func=action,
diff --git a/tests/template_tests/templatetags/custom.py b/tests/template_tests/templatetags/custom.py
index bf201e74e9..f89ed1d9d3 100644
--- a/tests/template_tests/templatetags/custom.py
+++ b/tests/template_tests/templatetags/custom.py
@@ -268,62 +268,6 @@ def simple_unlimited_args_kwargs_block(content, one, two="hi", *args, **kwargs):
     )
 
 
-@register.simple_block_tag(takes_context=True)
-def simple_block_tag_without_context_parameter(arg):
-    """Expected simple_block_tag_without_context_parameter __doc__"""
-    return "Expected result"
-
-
-@register.simple_block_tag
-def simple_tag_without_content_parameter(arg):
-    """Expected simple_tag_without_content_parameter __doc__"""
-    return "Expected result"
-
-
-@register.simple_block_tag(takes_context=True)
-def simple_tag_with_context_without_content_parameter(context, arg):
-    """Expected simple_tag_with_context_without_content_parameter __doc__"""
-    return "Expected result"
-
-
-@register.simple_tag(takes_context=True)
-def simple_tag_without_context_parameter(arg):
-    """Expected simple_tag_without_context_parameter __doc__"""
-    return "Expected result"
-
-
-simple_tag_without_context_parameter.anything = (
-    "Expected simple_tag_without_context_parameter __dict__"
-)
-
-
-@register.simple_block_tag(takes_context=True)
-def simple_tag_takes_context_without_params_block():
-    """Expected simple_tag_takes_context_without_params_block __doc__"""
-    return "Expected result"
-
-
-@register.simple_tag(takes_context=True)
-def simple_tag_takes_context_without_params():
-    """Expected simple_tag_takes_context_without_params __doc__"""
-    return "Expected result"
-
-
-simple_tag_takes_context_without_params.anything = (
-    "Expected simple_tag_takes_context_without_params __dict__"
-)
-
-
-@register.simple_block_tag
-def simple_block_tag_without_content():
-    return "Expected result"
-
-
-@register.simple_block_tag(takes_context=True)
-def simple_block_tag_with_context_without_content():
-    return "Expected result"
-
-
 @register.simple_tag(takes_context=True)
 def escape_naive(context):
     """A tag that doesn't even think about escaping issues"""
diff --git a/tests/template_tests/templatetags/inclusion.py b/tests/template_tests/templatetags/inclusion.py
index ea749a43b5..741eb250a2 100644
--- a/tests/template_tests/templatetags/inclusion.py
+++ b/tests/template_tests/templatetags/inclusion.py
@@ -269,28 +269,6 @@ inclusion_unlimited_args_kwargs.anything = (
 )
 
 
-@register.inclusion_tag("inclusion.html", takes_context=True)
-def inclusion_tag_without_context_parameter(arg):
-    """Expected inclusion_tag_without_context_parameter __doc__"""
-    return {}
-
-
-inclusion_tag_without_context_parameter.anything = (
-    "Expected inclusion_tag_without_context_parameter __dict__"
-)
-
-
-@register.inclusion_tag("inclusion.html", takes_context=True)
-def inclusion_tag_takes_context_without_params():
-    """Expected inclusion_tag_takes_context_without_params __doc__"""
-    return {}
-
-
-inclusion_tag_takes_context_without_params.anything = (
-    "Expected inclusion_tag_takes_context_without_params __dict__"
-)
-
-
 @register.inclusion_tag("inclusion_extends1.html")
 def inclusion_extends1():
     return {}
diff --git a/tests/template_tests/test_custom.py b/tests/template_tests/test_custom.py
index 424c110875..c146da5ff7 100644
--- a/tests/template_tests/test_custom.py
+++ b/tests/template_tests/test_custom.py
@@ -2,7 +2,7 @@ import os
 
 from django.template import Context, Engine, TemplateSyntaxError
 from django.template.base import Node
-from django.template.library import InvalidTemplateLibrary
+from django.template.library import InvalidTemplateLibrary, Library
 from django.test import SimpleTestCase
 from django.test.utils import extend_sys_path
 
@@ -216,10 +216,6 @@ class SimpleTagTests(TagTestCase):
         self.verify_tag(
             custom.simple_unlimited_args_kwargs, "simple_unlimited_args_kwargs"
         )
-        self.verify_tag(
-            custom.simple_tag_without_context_parameter,
-            "simple_tag_without_context_parameter",
-        )
 
     def test_simple_tag_missing_context(self):
         # The 'context' parameter must be present when takes_context is True
@@ -228,9 +224,10 @@ class SimpleTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_tag_without_context_parameter 123 %}"
-            )
+
+            @Library().simple_tag(takes_context=True)
+            def simple_tag_without_context_parameter(arg):
+                return "Expected result"
 
     def test_simple_tag_missing_context_no_params(self):
         msg = (
@@ -238,9 +235,10 @@ class SimpleTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_tag_takes_context_without_params %}"
-            )
+
+            @Library().simple_tag(takes_context=True)
+            def simple_tag_takes_context_without_params():
+                return "Expected result"
 
 
 class SimpleBlockTagTests(TagTestCase):
@@ -423,18 +421,6 @@ class SimpleBlockTagTests(TagTestCase):
                 "of: endsimple_one_default_block.",
                 "{% load custom %}{% simple_one_default_block %}Some content",
             ),
-            (
-                "'simple_tag_without_content_parameter' must have a first argument "
-                "of 'content'",
-                "{% load custom %}{% simple_tag_without_content_parameter %}",
-            ),
-            (
-                "'simple_tag_with_context_without_content_parameter' is decorated with "
-                "takes_context=True so it must have a first argument of 'context' and "
-                "a second argument of 'content'",
-                "{% load custom %}"
-                "{% simple_tag_with_context_without_content_parameter %}",
-            ),
         ]
 
         for entry in errors:
@@ -485,10 +471,10 @@ class SimpleBlockTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_block_tag_without_context_parameter 123 %}"
-                "{% endsimple_block_tag_without_context_parameter %}"
-            )
+
+            @Library().simple_block_tag(takes_context=True)
+            def simple_block_tag_without_context_parameter(arg):
+                return "Expected result"
 
     def test_simple_block_tag_missing_context_no_params(self):
         msg = (
@@ -496,10 +482,10 @@ class SimpleBlockTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_tag_takes_context_without_params_block %}"
-                "{% endsimple_tag_takes_context_without_params_block %}"
-            )
+
+            @Library().simple_block_tag(takes_context=True)
+            def simple_tag_takes_context_without_params_block():
+                return "Expected result"
 
     def test_simple_block_tag_missing_content(self):
         # The 'content' parameter must be present when takes_context is True
@@ -507,10 +493,10 @@ class SimpleBlockTagTests(TagTestCase):
             "'simple_block_tag_without_content' must have a first argument of 'content'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_block_tag_without_content %}"
-                "{% endsimple_block_tag_without_content %}"
-            )
+
+            @Library().simple_block_tag
+            def simple_block_tag_without_content():
+                return "Expected result"
 
     def test_simple_block_tag_with_context_missing_content(self):
         # The 'content' parameter must be present when takes_context is True
@@ -520,10 +506,10 @@ class SimpleBlockTagTests(TagTestCase):
             "second argument of 'content'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load custom %}{% simple_block_tag_with_context_without_content %}"
-                "{% endsimple_block_tag_with_context_without_content %}"
-            )
+
+            @Library().simple_block_tag(takes_context=True)
+            def simple_block_tag_with_context_without_content():
+                return "Expected result"
 
     def test_simple_block_gets_context(self):
         c = Context({"name": "Jack & Jill"})
@@ -720,9 +706,10 @@ class InclusionTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load inclusion %}{% inclusion_tag_without_context_parameter 123 %}"
-            )
+
+            @Library().inclusion_tag("inclusion.html", takes_context=True)
+            def inclusion_tag_without_context_parameter(arg):
+                return {}
 
     def test_include_tag_missing_context_no_params(self):
         msg = (
@@ -730,9 +717,10 @@ class InclusionTagTests(TagTestCase):
             "takes_context=True so it must have a first argument of 'context'"
         )
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
-            self.engine.from_string(
-                "{% load inclusion %}{% inclusion_tag_takes_context_without_params %}"
-            )
+
+            @Library().inclusion_tag("inclusion.html", takes_context=True)
+            def inclusion_tag_takes_context_without_params():
+                return {}
 
     def test_inclusion_tags_from_template(self):
         c = Context({"value": 42})
@@ -822,10 +810,6 @@ class InclusionTagTests(TagTestCase):
         self.verify_tag(
             inclusion.inclusion_only_unlimited_args, "inclusion_only_unlimited_args"
         )
-        self.verify_tag(
-            inclusion.inclusion_tag_without_context_parameter,
-            "inclusion_tag_without_context_parameter",
-        )
         self.verify_tag(inclusion.inclusion_tag_use_l10n, "inclusion_tag_use_l10n")
         self.verify_tag(
             inclusion.inclusion_unlimited_args_kwargs, "inclusion_unlimited_args_kwargs"