fix(warnings): Do not warn for default handlers (#3569)

* fix(warnings): Do not warn for default handlers
* test: add test to check (lack of) warnings

---------

Co-authored-by: Alc-Alc <alc@localhost>

docs/conf.py

@@ -184,7 +184,7 @@
     ("py:exc", "HTTPExceptions"),
     (PY_CLASS, "litestar.template.Template"),
     (PY_CLASS, "litestar.middleware.compression.gzip_facade.GzipCompression"),
-    (PY_CLASS, "litestar.handlers.http_handlers.decorators._SubclassWarningMixin"),
+    (PY_CLASS, "litestar.handlers.http_handlers.decorators._subclass_warning"),
 ]
 
 nitpick_ignore_regex = [

litestar/handlers/http_handlers/decorators.py

@@ -46,17 +46,16 @@
 MSG_SEMANTIC_ROUTE_HANDLER_WITH_HTTP = "semantic route handlers cannot define http_method"
 
 
-class _SubclassWarningMixin:
-    def __init_subclass__(cls, **kwargs: Any) -> None:
-        warnings.warn(
-            "Semantic HTTP route handler classes are deprecated and will be replaced by "
-            "functional decorators in Litestar 3.0.",
-            category=DeprecationWarning,
-            stacklevel=2,
-        )
+def _subclass_warning() -> None:
+    warnings.warn(
+        "Semantic HTTP route handler classes are deprecated and will be replaced by "
+        "functional decorators in Litestar 3.0.",
+        category=DeprecationWarning,
+        stacklevel=2,
+    )
 
 
-class delete(HTTPRouteHandler, _SubclassWarningMixin):
+class delete(HTTPRouteHandler):
     """DELETE Route Decorator.
 
     Use this decorator to decorate an HTTP handler for DELETE requests.
@@ -227,8 +226,11 @@ def __init__(
             **kwargs,
         )
 
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()
+
 
-class get(HTTPRouteHandler, _SubclassWarningMixin):
+class get(HTTPRouteHandler):
     """GET Route Decorator.
 
     Use this decorator to decorate an HTTP handler for GET requests.
@@ -400,8 +402,11 @@ def __init__(
             **kwargs,
         )
 
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()
+
 
-class head(HTTPRouteHandler, _SubclassWarningMixin):
+class head(HTTPRouteHandler):
     """HEAD Route Decorator.
 
     Use this decorator to decorate an HTTP handler for HEAD requests.
@@ -577,6 +582,9 @@ def __init__(
             **kwargs,
         )
 
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()
+
     def _validate_handler_function(self) -> None:
         """Validate the route handler function once it is set by inspecting its return annotations."""
         super()._validate_handler_function()
@@ -591,7 +599,7 @@ def _validate_handler_function(self) -> None:
             raise ImproperlyConfiguredException("A response to a head request should not have a body")
 
 
-class patch(HTTPRouteHandler, _SubclassWarningMixin):
+class patch(HTTPRouteHandler):
     """PATCH Route Decorator.
 
     Use this decorator to decorate an HTTP handler for PATCH requests.
@@ -762,8 +770,11 @@ def __init__(
             **kwargs,
         )
 
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()
+
 
-class post(HTTPRouteHandler, _SubclassWarningMixin):
+class post(HTTPRouteHandler):
     """POST Route Decorator.
 
     Use this decorator to decorate an HTTP handler for POST requests.
@@ -934,8 +945,11 @@ def __init__(
             **kwargs,
         )
 
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()
 
-class put(HTTPRouteHandler, _SubclassWarningMixin):
+
+class put(HTTPRouteHandler):
     """PUT Route Decorator.
 
     Use this decorator to decorate an HTTP handler for PUT requests.
@@ -1105,3 +1119,6 @@ def __init__(
             type_encoders=type_encoders,
             **kwargs,
         )
+
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        _subclass_warning()

tests/unit/test_handlers/test_http_handlers/test_deprecation.py

@@ -1,5 +1,8 @@
 from __future__ import annotations
 
+from importlib import reload
+from warnings import catch_warnings, simplefilter
+
 import pytest
 
 from litestar.handlers import delete, get, head, patch, post, put
@@ -11,3 +14,15 @@ def test_subclass_warns_deprecation(handler_cls: get | post | put | patch | dele
 
         class SubClass(handler_cls):  # type: ignore[valid-type, misc]
             pass
+
+
+def test_default_no_warns() -> None:
+    with catch_warnings(record=True) as warnings:
+        simplefilter("always")
+        import litestar.handlers.http_handlers.decorators
+
+        reload(litestar.handlers.http_handlers.decorators)
+        assert len(warnings) == 0
+
+        # revert to previous filter
+        simplefilter("default")