fix: attribute user-triggered warnings to the caller via stacklevel

manim/mobject/graphing/probability.py

@@ -292,7 +292,8 @@ def __init__(
     ):
         if isinstance(bar_colors, str):
             logger.warning(
-                "Passing a string to `bar_colors` has been deprecated since v0.15.2 and will be removed after v0.17.0, the parameter must be a list.  "
+                "Passing a string to `bar_colors` has been deprecated since v0.15.2 and will be removed after v0.17.0, the parameter must be a list.  ",
+                stacklevel=2,
             )
             bar_colors = list(bar_colors)
 

manim/mobject/mobject.py

@@ -504,6 +504,7 @@ def _insert_submobjects(self, index: int, mobjects: Sequence[Mobject]) -> Self:
             logger.warning(
                 "Attempted adding some Mobject as a child more than once, "
                 "this is not possible. Repetitions are ignored.",
+                stacklevel=3,
             )
 
         if not self.submobjects:

manim/mobject/opengl/opengl_mobject.py

@@ -863,6 +863,7 @@ def _insert_submobjects(
             logger.warning(
                 "Attempted adding some Mobject as a child more than once, "
                 "this is not possible. Repetitions are ignored.",
+                stacklevel=3,
             )
 
         if not self._submobjects:

manim/mobject/text/text_mobject.py

@@ -487,7 +487,7 @@ def __init__(
                 elif font.title() in fonts_list:
                     font = font.title()
                 else:
-                    logger.warning(f"Font {font} not in {fonts_list}.")
+                    logger.warning(f"Font {font} not in {fonts_list}.", stacklevel=2)
         self.font = font
         self._font_size = float(font_size)
         # needs to be a float or else size is inflated when font_size = 24
@@ -1214,7 +1214,7 @@ def __init__(
                 elif font.title() in fonts_list:
                     font = font.title()
                 else:
-                    logger.warning(f"Font {font} not in {fonts_list}.")
+                    logger.warning(f"Font {font} not in {fonts_list}.", stacklevel=2)
         self.font = font
         self._font_size = float(font_size)
         self.slant = slant

manim/mobject/three_d/three_dimensions.py

@@ -295,7 +295,8 @@ def param_surface(u, v):
         if colorscale is None:
             logger.warning(
                 "The value passed to the colorscale keyword argument was None, "
-                "the surface fill color has not been changed"
+                "the surface fill color has not been changed",
+                stacklevel=2,
             )
             return self
         colorscale_list = list(colorscale)

manim/scene/scene.py

@@ -1160,7 +1160,8 @@ def validate_run_time(
                 f"The original {parameter_name} of {method_name}, "
                 f"{run_time:g} seconds, is too short for the current frame "
                 f"rate of {fps:g} FPS. Rendering with the shortest possible "
-                f"{parameter_name} of {seconds_per_frame:g} seconds instead."
+                f"{parameter_name} of {seconds_per_frame:g} seconds instead.",
+                stacklevel=3,
             )
             run_time = seconds_per_frame
 
@@ -1602,10 +1603,13 @@ def interact(self, shell: Any, keyboard_thread: threading.Thread) -> None:
     def embed(self) -> None:
         assert isinstance(self.renderer, OpenGLRenderer)
         if not self.session_spec.presentation.live_preview:
-            logger.warning("Called embed() while no live preview window is available.")
+            logger.warning(
+                "Called embed() while no live preview window is available.",
+                stacklevel=2,
+            )
             return
         if self.renderer.file_writer.output_spec.enabled:
-            logger.warning("embed() is skipped while writing to a file.")
+            logger.warning("embed() is skipped while writing to a file.", stacklevel=2)
             return
 
         self.renderer.animation_start_time = 0

manim/utils/deprecation.py

@@ -245,7 +245,7 @@ def deprecate(func: Callable[..., T], *args: Any, **kwargs: Any) -> T:
             The return value of the given callable when being passed the given
             arguments.
         """
-        logger.warning(warning_msg())
+        logger.warning(warning_msg(), stacklevel=3)
         return func(*args, **kwargs)
 
     if type(func).__name__ != "function":
@@ -529,7 +529,7 @@ def deprecate_params(func: Callable[..., T], *args: Any, **kwargs: Any) -> T:
         used = [param for param in params if param in kwargs]
 
         if len(used) > 0:
-            logger.warning(warning_msg(func, used))
+            logger.warning(warning_msg(func, used), stacklevel=3)
             redirect_params(kwargs, used)
         return func(*args, **kwargs)
 

tests/module/mobject/text/test_text_mobject.py

@@ -1,8 +1,5 @@
 from __future__ import annotations
 
-from contextlib import redirect_stdout
-from io import StringIO
-
 import pytest
 
 from manim.mobject.text.text_mobject import MarkupText, Text
@@ -19,13 +16,13 @@ def test_font_size():
     assert round(markuptext_string.font_size, 5) == 14.4
 
 
-def test_font_warnings():
+def test_font_warnings(manim_caplog):
     def warning_printed(font: str, **kwargs) -> bool:
-        io = StringIO()
-        with redirect_stdout(io):
-            Text("hi!", font=font, **kwargs)
-        txt = io.getvalue()
-        return "Font" in txt and "not in" in txt
+        # Inspect the log records rather than rendered console output: the
+        # latter is wrapped to the terminal width, which can split the message.
+        manim_caplog.clear()
+        Text("hi!", font=font, **kwargs)
+        return any("not in" in record.getMessage() for record in manim_caplog.records)
 
     # check for normal fonts (no warning)
     assert not warning_printed("System-ui", warn_missing_font=True)

tests/module/utils/test_warning_stacklevel.py

@@ -0,0 +1,69 @@
+"""Warnings caused by user code should be attributed to the caller.
+
+Each ``logger.warning`` that a user's own call can trigger passes ``stacklevel``,
+so the emitted record points at the line the user wrote rather than at the line
+inside Manim where the warning happens to live.
+"""
+
+from __future__ import annotations
+
+import inspect
+import linecache
+from logging import LogRecord
+
+from manim import Mobject
+from manim.utils.deprecation import deprecated, deprecated_params
+
+
+@deprecated(since="v0.1.0", message="Use something else.")
+def _deprecated_function() -> int:
+    return 1
+
+
+@deprecated_params(params="old", since="v0.1.0", message="Use new instead.")
+def _function_with_deprecated_param(**kwargs: int) -> int:
+    return 1
+
+
+def _assert_blames_caller(record: LogRecord, source_fragment: str) -> None:
+    """Assert the record points at the caller's own statement.
+
+    Checked by source text rather than a line number so the test survives
+    reformatting.
+    """
+    caller = inspect.currentframe().f_back.f_code.co_name
+    assert record.pathname == __file__, (
+        f"warning was attributed to {record.pathname}, expected the calling module"
+    )
+    assert record.funcName == caller, (
+        f"warning was attributed to {record.funcName}(), expected {caller}()"
+    )
+    blamed_line = linecache.getline(record.pathname, record.lineno)
+    assert source_fragment in blamed_line, (
+        f"warning pointed at {blamed_line.strip()!r}, "
+        f"expected the line containing {source_fragment!r}"
+    )
+
+
+def test_deprecated_function_warning_points_at_caller(manim_caplog):
+    _deprecated_function()
+    _assert_blames_caller(manim_caplog.records[0], "_deprecated_function()")
+
+
+def test_deprecated_param_warning_points_at_caller(manim_caplog):
+    _function_with_deprecated_param(old=2)
+    _assert_blames_caller(
+        manim_caplog.records[0], "_function_with_deprecated_param(old=2)"
+    )
+
+
+def test_duplicate_add_warning_points_at_caller(manim_caplog):
+    parent, child = Mobject(), Mobject()
+    parent.add(child, child)
+    _assert_blames_caller(manim_caplog.records[0], "parent.add(child, child)")
+
+
+def test_duplicate_add_to_back_warning_points_at_caller(manim_caplog):
+    parent, child = Mobject(), Mobject()
+    parent.add_to_back(child, child)
+    _assert_blames_caller(manim_caplog.records[0], "parent.add_to_back(child, child)")