improve warning stack level + fix minor issue

Author: rmorshea

noxfile.py

@@ -187,6 +187,7 @@ def test_python_suite(session: Session) -> None:
         args = ["coverage", "run", "--source=src/idom", "--module", *args]
         install_idom_dev(session)
     else:
+        args.remove("--no-cov")
         session.log("Coverage won't be checked")
         session.install(".[all]")
 

src/idom/_option.py

@@ -1,9 +1,11 @@
 from __future__ import annotations
 
 import os
-import warnings
+from inspect import currentframe
 from logging import getLogger
-from typing import Any, Callable, Generic, TypeVar, cast
+from types import FrameType
+from typing import Any, Callable, Generic, Iterator, TypeVar, cast
+from warnings import warn
 
 
 _O = TypeVar("_O")
@@ -129,12 +131,32 @@ def __init__(self, new_opt: Option[_O], name: str) -> None:
 
     @property  # type: ignore
     def _current(self) -> _O:
-        warnings.warn(
+        warn(
             f"{self.name!r} has been renamed to {self._new_opt.name!r}",
             DeprecationWarning,
+            stacklevel=_frame_depth_in_module() + 1,
         )
         return self._new_opt.current
 
     @_current.setter
     def _current(self, new: _O) -> None:
         self._new_opt.current = new
+
+
+def _frame_depth_in_module() -> int:
+    depth = -1  # use -1 to ignore current frame
+    for frame in _iter_frames():
+        if frame.f_globals.get("__name__") != __name__:
+            break
+        depth += 1
+    return depth
+
+
+def _iter_frames() -> Iterator[FrameType]:
+    frame = currentframe()
+    if frame is None:
+        return  # pragma: no cover
+    frame = frame.f_back  # ignore current frame
+    while frame is not None:
+        yield frame
+        frame = frame.f_back