Added explicit stacklevel arguments to all warnings

docs/versionhistory.rst

@@ -5,6 +5,8 @@ This library adheres to `Semantic Versioning 2.0 <https://semver.org/#semantic-v
 
 **UNRELEASED**
 
+- Improved warnings by ensuring that they target user code and not Typeguard internal
+  code
 - Fixed ``warn_on_error()`` not showing where the type violation actually occurred
 - Fixed local assignment to ``*args`` or ``**kwargs`` being type checked incorrectly
 - Fixed ``TypeError`` on ``check_type(..., None)``

src/typeguard/_checkers.py

@@ -35,7 +35,7 @@
 from ._config import ForwardRefPolicy, global_config
 from ._exceptions import TypeCheckError, TypeHintWarning
 from ._memo import CallMemo, TypeCheckMemo
-from ._utils import evaluate_forwardref, get_type_name, qualified_name
+from ._utils import evaluate_forwardref, get_stacklevel, get_type_name, qualified_name
 
 if sys.version_info >= (3, 11):
     from typing import (
@@ -572,7 +572,8 @@ def check_protocol(
         warnings.warn(
             f"Typeguard cannot check the {origin_type.__qualname__} protocol because "
             f"it is a non-runtime protocol. If you would like to type check this "
-            f"protocol, please use @typing.runtime_checkable"
+            f"protocol, please use @typing.runtime_checkable",
+            stacklevel=get_stacklevel(),
         )
 
 
@@ -637,6 +638,7 @@ def check_type_internal(value: Any, annotation: Any, memo: TypeCheckMemo) -> Non
                 warnings.warn(
                     f"Cannot resolve forward reference {annotation.__forward_arg__!r}",
                     TypeHintWarning,
+                    stacklevel=get_stacklevel(),
                 )
 
             return
@@ -770,12 +772,15 @@ def load_plugins() -> None:
             plugin = ep.load()
         except Exception as exc:
             warnings.warn(
-                f"Failed to load plugin {ep.name!r}: " f"{qualified_name(exc)}: {exc}"
+                f"Failed to load plugin {ep.name!r}: " f"{qualified_name(exc)}: {exc}",
+                stacklevel=2,
             )
             continue
 
         if not callable(plugin):
-            warnings.warn(f"Plugin {ep} returned a non-callable object: {plugin!r}")
+            warnings.warn(
+                f"Plugin {ep} returned a non-callable object: {plugin!r}", stacklevel=2
+            )
             continue
 
         checker_lookup_functions.insert(0, plugin)

src/typeguard/_decorators.py

@@ -11,7 +11,7 @@
 from ._config import global_config
 from ._exceptions import InstrumentationWarning
 from ._transformer import TypeguardTransformer
-from ._utils import function_name, is_method_of
+from ._utils import function_name, get_stacklevel, is_method_of
 
 if TYPE_CHECKING:
     from typeshed.stdlib.types import _Cell
@@ -177,6 +177,7 @@ def typechecked(target: T_CallableOrType | None = None) -> Any:
         warn(
             f"{retval} -- not typechecking {function_name(target)}",
             InstrumentationWarning,
+            stacklevel=get_stacklevel(),
         )
         return target
 

src/typeguard/_functions.py

@@ -11,7 +11,7 @@
 from ._config import global_config
 from ._exceptions import TypeCheckError, TypeCheckWarning
 from ._memo import CallMemo, TypeCheckMemo
-from ._utils import qualified_name
+from ._utils import get_stacklevel, qualified_name
 
 if sys.version_info >= (3, 11):
     from typing import Never
@@ -308,7 +308,7 @@ def warn_on_error(exc: TypeCheckError, memo: TypeCheckMemo) -> None:
     :attr:`TypeCheckConfiguration.typecheck_fail_callback`.
 
     """
-    warnings.warn(TypeCheckWarning(str(exc)), stacklevel=3)
+    warnings.warn(TypeCheckWarning(str(exc)), stacklevel=get_stacklevel())
 
 
 @contextmanager

src/typeguard/_pytest_plugin.py

@@ -65,6 +65,7 @@ def pytest_configure(config: Config) -> None:
                     f"typeguard cannot check these packages because they are already "
                     f"imported: {', '.join(already_imported_packages)}",
                     InstrumentationWarning,
+                    stacklevel=1,
                 )
 
         install_import_hook(packages=packages)

src/typeguard/_utils.py

@@ -3,8 +3,9 @@
 import inspect
 import sys
 from importlib import import_module
-from types import CodeType, FunctionType
-from typing import TYPE_CHECKING, Any, Callable, ForwardRef, Union
+from inspect import currentframe
+from types import CodeType, FrameType, FunctionType
+from typing import TYPE_CHECKING, Any, Callable, ForwardRef, Union, cast
 from weakref import WeakValueDictionary
 
 if TYPE_CHECKING:
@@ -137,3 +138,13 @@ def is_method_of(obj: object, cls: type) -> bool:
         and obj.__module__ == cls.__module__
         and obj.__qualname__.startswith(cls.__qualname__ + ".")
     )
+
+
+def get_stacklevel() -> int:
+    level = 1
+    frame = cast(FrameType, currentframe()).f_back
+    while frame and frame.f_globals.get("__name__", "").startswith("typeguard."):
+        level += 1
+        frame = frame.f_back
+
+    return level

tests/test_checkers.py

@@ -877,14 +877,18 @@ def meth(self) -> None:
 
         with pytest.warns(
             UserWarning, match=r"Typeguard cannot check the StaticProtocol protocol.*"
-        ):
+        ) as warning:
             check_type(Foo(), StaticProtocol)
 
+        assert warning.list[0].filename == __file__
+
         with pytest.warns(
             UserWarning, match=r"Typeguard cannot check the StaticProtocol protocol.*"
-        ):
+        ) as warning:
             check_type(Foo, Type[StaticProtocol])
 
+        assert warning.list[0].filename == __file__
+
     def test_fail_non_method_members(self):
         class Foo:
             val = 1