From f1ce5122253882a20b6714adf728eccfa41162e9 Mon Sep 17 00:00:00 2001
From: Abulafia <44573666+abul4fia@users.noreply.github.com>
Date: Mon, 15 Jul 2024 00:50:44 +0200
Subject: [PATCH] Fixed behavior of `config.background_opacity < 1` and
 duplicated log messages (#3680)

* Fixes #3614

Setting background_transparency=0.0 should have the same effect than
setting transparent=True. The output format must be compatible
with transparency (.mov, .webm). Otherwise ffpmeg fails.

This patch ensures that background_transparency=0.0 triggers the
change of the output format. Also a WARNING is raised about
the change in the output format.

I want to thank @SirJamesClarkMaxwell for inspiring me to tackle
this issue.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* test config.background_opacity < 1

* fix config behavior for config.background_opacity < 1

* fix logger messages being emitted twice

* actually cleanup usage of loggers, remove logger-imports; black

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* dry_run fixture

* remove debug print

* applied suggestion from review

* remove custom fixture from test_deprecation, use manim_caplog

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Benjamin Hackl <devel@benjamin-hackl.at>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 manim/_config/logger_utils.py                 |   1 +
 manim/_config/utils.py                        |  22 ++-
 manim/cli/render/global_options.py            |   5 +-
 manim/cli/render/render_options.py            |   5 +-
 manim/renderer/shader_wrapper.py              |   5 +-
 manim/utils/deprecation.py                    |   3 +-
 manim/utils/testing/_frames_testers.py        |   5 +-
 tests/conftest.py                             |  10 ++
 tests/helpers/graphical_units.py              |   4 +-
 tests/module/animation/test_animation.py      |   8 +-
 .../mobject/geometry/test_unit_geometry.py    |   5 +-
 tests/module/utils/test_deprecation.py        | 128 ++++++++----------
 tests/test_config.py                          |  12 ++
 13 files changed, 121 insertions(+), 92 deletions(-)

diff --git a/manim/_config/logger_utils.py b/manim/_config/logger_utils.py
index f3b43f8f78..9205635eef 100644
--- a/manim/_config/logger_utils.py
+++ b/manim/_config/logger_utils.py
@@ -99,6 +99,7 @@ def make_logger(
     logger = logging.getLogger("manim")
     logger.addHandler(rich_handler)
     logger.setLevel(verbosity)
+    logger.propagate = False
 
     if not (libav_logger := logging.getLogger()).hasHandlers():
         libav_logger.addHandler(rich_handler)
diff --git a/manim/_config/utils.py b/manim/_config/utils.py
index 6c2492d95e..46613e8d74 100644
--- a/manim/_config/utils.py
+++ b/manim/_config/utils.py
@@ -40,6 +40,8 @@
 
 __all__ = ["config_file_paths", "make_config_parser", "ManimConfig", "ManimFrame"]
 
+logger = logging.getLogger("manim")
+
 
 def config_file_paths() -> list[Path]:
     """The paths where ``.cfg`` files will be searched for.
@@ -799,7 +801,7 @@ def digest_args(self, args: argparse.Namespace) -> Self:
             try:
                 self.upto_animation_number = nflag[1]
             except Exception:
-                logging.getLogger("manim").info(
+                logger.info(
                     f"No end scene number specified in -n option. Rendering from {nflag[0]} onwards...",
                 )
 
@@ -1038,7 +1040,7 @@ def verbosity(self, val: str) -> None:
             val,
             ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
         )
-        logging.getLogger("manim").setLevel(val)
+        logger.setLevel(val)
 
     @property
     def format(self) -> str:
@@ -1054,7 +1056,7 @@ def format(self, val: str) -> None:
         )
         self.resolve_movie_file_extension(self.transparent)
         if self.format == "webm":
-            logging.getLogger("manim").warning(
+            logger.warning(
                 "Output format set as webm, this can be slower than other formats",
             )
 
@@ -1272,6 +1274,8 @@ def background_opacity(self) -> float:
     @background_opacity.setter
     def background_opacity(self, value: float) -> None:
         self._set_between("background_opacity", value, 0, 1)
+        if self.background_opacity < 1:
+            self.resolve_movie_file_extension(is_transparent=True)
 
     @property
     def frame_size(self) -> tuple[int, int]:
@@ -1306,8 +1310,8 @@ def quality(self, value: str | None) -> None:
 
     @property
     def transparent(self) -> bool:
-        """Whether the background opacity is 0.0 (-t)."""
-        return self._d["background_opacity"] == 0.0
+        """Whether the background opacity is less than 1.0 (-t)."""
+        return self._d["background_opacity"] < 1.0
 
     @transparent.setter
     def transparent(self, value: bool) -> None:
@@ -1425,6 +1429,7 @@ def window_size(self, value: str) -> None:
         self._d.__setitem__("window_size", value)
 
     def resolve_movie_file_extension(self, is_transparent: bool) -> None:
+        prev_file_extension = self.movie_file_extension
         if is_transparent:
             self.movie_file_extension = ".webm" if self.format == "webm" else ".mov"
         elif self.format == "webm":
@@ -1433,6 +1438,11 @@ def resolve_movie_file_extension(self, is_transparent: bool) -> None:
             self.movie_file_extension = ".mov"
         else:
             self.movie_file_extension = ".mp4"
+        if self.movie_file_extension != prev_file_extension:
+            logger.warning(
+                f"Output format changed to '{self.movie_file_extension}' "
+                "to support transparency",
+            )
 
     @property
     def enable_gui(self) -> bool:
@@ -1778,7 +1788,7 @@ def tex_template_file(self) -> Path:
     def tex_template_file(self, val: str) -> None:
         if val:
             if not os.access(val, os.R_OK):
-                logging.getLogger("manim").warning(
+                logger.warning(
                     f"Custom TeX template {val} not found or not readable.",
                 )
             else:
diff --git a/manim/cli/render/global_options.py b/manim/cli/render/global_options.py
index d7424dd1ee..5941d4fd68 100644
--- a/manim/cli/render/global_options.py
+++ b/manim/cli/render/global_options.py
@@ -1,13 +1,14 @@
 from __future__ import annotations
 
+import logging
 import re
 
 from cloup import Choice, option, option_group
 
-from ... import logger
-
 __all__ = ["global_options"]
 
+logger = logging.getLogger("manim")
+
 
 def validate_gui_location(ctx, param, value):
     if value:
diff --git a/manim/cli/render/render_options.py b/manim/cli/render/render_options.py
index 5a2d992db8..21a91ce393 100644
--- a/manim/cli/render/render_options.py
+++ b/manim/cli/render/render_options.py
@@ -1,15 +1,16 @@
 from __future__ import annotations
 
+import logging
 import re
 
 from cloup import Choice, option, option_group
 
 from manim.constants import QUALITIES, RendererType
 
-from ... import logger
-
 __all__ = ["render_options"]
 
+logger = logging.getLogger("manim")
+
 
 def validate_scene_range(ctx, param, value):
     try:
diff --git a/manim/renderer/shader_wrapper.py b/manim/renderer/shader_wrapper.py
index 00e111aad6..8a2b0d1fbe 100644
--- a/manim/renderer/shader_wrapper.py
+++ b/manim/renderer/shader_wrapper.py
@@ -1,14 +1,13 @@
 from __future__ import annotations
 
 import copy
+import logging
 import re
 from pathlib import Path
 
 import moderngl
 import numpy as np
 
-from .. import logger
-
 # Mobjects that should be rendered with
 # the same shader will be organized and
 # clumped together based on keeping track
@@ -17,6 +16,8 @@
 
 __all__ = ["ShaderWrapper"]
 
+logger = logging.getLogger("manim")
+
 
 def get_shader_dir():
     return Path(__file__).parent / "shaders"
diff --git a/manim/utils/deprecation.py b/manim/utils/deprecation.py
index 2d443c5e72..4fd76880b4 100644
--- a/manim/utils/deprecation.py
+++ b/manim/utils/deprecation.py
@@ -6,13 +6,14 @@
 
 
 import inspect
+import logging
 import re
 from collections.abc import Iterable
 from typing import Any, Callable
 
 from decorator import decorate, decorator
 
-from .. import logger
+logger = logging.getLogger("manim")
 
 
 def _get_callable_info(callable: Callable) -> tuple[str, str]:
diff --git a/manim/utils/testing/_frames_testers.py b/manim/utils/testing/_frames_testers.py
index be0bc38447..a0ca9ddd99 100644
--- a/manim/utils/testing/_frames_testers.py
+++ b/manim/utils/testing/_frames_testers.py
@@ -1,18 +1,19 @@
 from __future__ import annotations
 
 import contextlib
+import logging
 import warnings
 from pathlib import Path
 
 import numpy as np
 
-from manim import logger
-
 from ._show_diff import show_diff_helper
 
 FRAME_ABSOLUTE_TOLERANCE = 1.01
 FRAME_MISMATCH_RATIO_TOLERANCE = 1e-5
 
+logger = logging.getLogger("manim")
+
 
 class _FramesTester:
     def __init__(self, file_path: Path, show_diff=False) -> None:
diff --git a/tests/conftest.py b/tests/conftest.py
index e69c1080d5..16962f4d2c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import logging
 import sys
 from pathlib import Path
 
@@ -45,6 +46,15 @@ def pytest_collection_modifyitems(config, items):
                 item.add_marker(slow_skip)
 
 
+@pytest.fixture
+def manim_caplog(caplog):
+    logger = logging.getLogger("manim")
+    logger.propagate = True
+    caplog.set_level(logging.INFO, logger="manim")
+    yield caplog
+    logger.propagate = False
+
+
 @pytest.fixture
 def config():
     saved = manim.config.copy()
diff --git a/tests/helpers/graphical_units.py b/tests/helpers/graphical_units.py
index 01eae516a9..1395559e52 100644
--- a/tests/helpers/graphical_units.py
+++ b/tests/helpers/graphical_units.py
@@ -2,14 +2,16 @@
 
 from __future__ import annotations
 
+import logging
 import tempfile
 from pathlib import Path
 
 import numpy as np
 
-from manim import logger
 from manim.scene.scene import Scene
 
+logger = logging.getLogger("manim")
+
 
 def set_test_scene(scene_object: type[Scene], module_name: str, config):
     """Function used to set up the test data for a new feature. This will basically set up a pre-rendered frame for a scene. This is meant to be used only
diff --git a/tests/module/animation/test_animation.py b/tests/module/animation/test_animation.py
index d57f57247e..448c0e76d6 100644
--- a/tests/module/animation/test_animation.py
+++ b/tests/module/animation/test_animation.py
@@ -15,20 +15,20 @@ def test_animation_forbidden_run_time(run_time):
         test_scene.play(FadeIn(None, run_time=run_time))
 
 
-def test_animation_run_time_shorter_than_frame_rate(caplog, config):
+def test_animation_run_time_shorter_than_frame_rate(manim_caplog, config):
     test_scene = Scene()
     test_scene.play(FadeIn(None, run_time=1 / (config.frame_rate + 1)))
     assert (
         "Original run time of FadeIn(Mobject) is shorter than current frame rate"
-        in caplog.text
+        in manim_caplog.text
     )
 
 
 @pytest.mark.parametrize("frozen_frame", [False, True])
-def test_wait_run_time_shorter_than_frame_rate(caplog, frozen_frame):
+def test_wait_run_time_shorter_than_frame_rate(manim_caplog, frozen_frame):
     test_scene = Scene()
     test_scene.wait(1e-9, frozen_frame=frozen_frame)
     assert (
         "Original run time of Wait(Mobject) is shorter than current frame rate"
-        in caplog.text
+        in manim_caplog.text
     )
diff --git a/tests/module/mobject/geometry/test_unit_geometry.py b/tests/module/mobject/geometry/test_unit_geometry.py
index 45f4da279f..e953ef2de3 100644
--- a/tests/module/mobject/geometry/test_unit_geometry.py
+++ b/tests/module/mobject/geometry/test_unit_geometry.py
@@ -15,8 +15,7 @@ def test_get_arc_center():
     )
 
 
-def test_BackgroundRectangle(caplog):
-    caplog.set_level(logging.INFO)
+def test_BackgroundRectangle(manim_caplog):
     c = Circle()
     bg = BackgroundRectangle(c)
     bg.set_style(fill_opacity=0.42)
@@ -24,5 +23,5 @@ def test_BackgroundRectangle(caplog):
     bg.set_style(fill_opacity=1, hello="world")
     assert (
         "Argument {'hello': 'world'} is ignored in BackgroundRectangle.set_style."
-        in caplog.text
+        in manim_caplog.text
     )
diff --git a/tests/module/utils/test_deprecation.py b/tests/module/utils/test_deprecation.py
index e498b8b196..c822a7cbdf 100644
--- a/tests/module/utils/test_deprecation.py
+++ b/tests/module/utils/test_deprecation.py
@@ -1,23 +1,13 @@
 from __future__ import annotations
 
-import logging
-
-import pytest
-
 from manim.utils.deprecation import deprecated, deprecated_params
 
 
-def _get_caplog_record_msg(warn_caplog_manim):
-    logger_name, level, message = warn_caplog_manim.record_tuples[0]
+def _get_caplog_record_msg(manim_caplog):
+    logger_name, level, message = manim_caplog.record_tuples[0]
     return message
 
 
-@pytest.fixture()
-def warn_caplog_manim(caplog):
-    caplog.set_level(logging.WARNING, logger="manim")
-    yield caplog
-
-
 @deprecated
 class Foo:
     def __init__(self):
@@ -77,11 +67,11 @@ def __init__(self):
 doc_admonition = "\n\n.. attention:: Deprecated\n  "
 
 
-def test_deprecate_class_no_args(warn_caplog_manim):
+def test_deprecate_class_no_args(manim_caplog):
     """Test the deprecation of a class (decorator with no arguments)."""
     f = Foo()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Foo has been deprecated and may be removed in a later version."
@@ -89,11 +79,11 @@ def test_deprecate_class_no_args(warn_caplog_manim):
     assert f.__doc__ == f"{doc_admonition}{msg}"
 
 
-def test_deprecate_class_since(warn_caplog_manim):
+def test_deprecate_class_since(manim_caplog):
     """Test the deprecation of a class (decorator with since argument)."""
     b = Bar()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Bar has been deprecated since v0.6.0 and may be removed in a later version."
@@ -101,11 +91,11 @@ def test_deprecate_class_since(warn_caplog_manim):
     assert b.__doc__ == f"The Bar class.{doc_admonition}{msg}"
 
 
-def test_deprecate_class_until(warn_caplog_manim):
+def test_deprecate_class_until(manim_caplog):
     """Test the deprecation of a class (decorator with until argument)."""
     bz = Baz()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Baz has been deprecated and is expected to be removed after 06/01/2021."
@@ -113,11 +103,11 @@ def test_deprecate_class_until(warn_caplog_manim):
     assert bz.__doc__ == f"The Baz class.{doc_admonition}{msg}"
 
 
-def test_deprecate_class_since_and_until(warn_caplog_manim):
+def test_deprecate_class_since_and_until(manim_caplog):
     """Test the deprecation of a class (decorator with since and until arguments)."""
     qx = Qux()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Qux has been deprecated since 0.7.0 and is expected to be removed after 0.9.0-rc2."
@@ -125,11 +115,11 @@ def test_deprecate_class_since_and_until(warn_caplog_manim):
     assert qx.__doc__ == f"{doc_admonition}{msg}"
 
 
-def test_deprecate_class_msg(warn_caplog_manim):
+def test_deprecate_class_msg(manim_caplog):
     """Test the deprecation of a class (decorator with msg argument)."""
     qu = Quux()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Quux has been deprecated and may be removed in a later version. Use something else."
@@ -137,11 +127,11 @@ def test_deprecate_class_msg(warn_caplog_manim):
     assert qu.__doc__ == f"{doc_admonition}{msg}"
 
 
-def test_deprecate_class_replacement(warn_caplog_manim):
+def test_deprecate_class_replacement(manim_caplog):
     """Test the deprecation of a class (decorator with replacement argument)."""
     qz = Quuz()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Quuz has been deprecated and may be removed in a later version. Use ReplaceQuuz instead."
@@ -150,11 +140,11 @@ def test_deprecate_class_replacement(warn_caplog_manim):
     assert qz.__doc__ == f"{doc_admonition}{doc_msg}"
 
 
-def test_deprecate_class_all(warn_caplog_manim):
+def test_deprecate_class_all(manim_caplog):
     """Test the deprecation of a class (decorator with all arguments)."""
     qza = QuuzAll()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class QuuzAll has been deprecated since 0.7.0 and is expected to be removed after 1.2.1. Use ReplaceQuuz instead. Don't use this please."
@@ -243,11 +233,11 @@ def quuz(self, **kwargs):
         return kwargs
 
 
-def test_deprecate_func_no_args(warn_caplog_manim):
+def test_deprecate_func_no_args(manim_caplog):
     """Test the deprecation of a method (decorator with no arguments)."""
     useless()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The function useless has been deprecated and may be removed in a later version."
@@ -255,12 +245,12 @@ def test_deprecate_func_no_args(warn_caplog_manim):
     assert useless.__doc__ == f"{doc_admonition}{msg}"
 
 
-def test_deprecate_func_in_class_since_and_message(warn_caplog_manim):
+def test_deprecate_func_in_class_since_and_message(manim_caplog):
     """Test the deprecation of a method within a class (decorator with since and message arguments)."""
     t = Top()
     t.mid_func()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The method Top.mid_func has been deprecated since 0.8.0 and may be removed in a later version. This method is useless."
@@ -268,11 +258,11 @@ def test_deprecate_func_in_class_since_and_message(warn_caplog_manim):
     assert t.mid_func.__doc__ == f"Middle function in Top.{doc_admonition}{msg}"
 
 
-def test_deprecate_nested_class_until_and_replacement(warn_caplog_manim):
+def test_deprecate_nested_class_until_and_replacement(manim_caplog):
     """Test the deprecation of a nested class (decorator with until and replacement arguments)."""
     n = Top().Nested()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The class Top.Nested has been deprecated and is expected to be removed after 1.4.0. Use Top.NewNested instead."
@@ -281,12 +271,12 @@ def test_deprecate_nested_class_until_and_replacement(warn_caplog_manim):
     assert n.__doc__ == f"{doc_admonition}{doc_msg}"
 
 
-def test_deprecate_nested_class_func_since_and_until(warn_caplog_manim):
+def test_deprecate_nested_class_func_since_and_until(manim_caplog):
     """Test the deprecation of a method within a nested class (decorator with since and until arguments)."""
     n = Top().NewNested()
     n.nested_func()
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The method Top.NewNested.nested_func has been deprecated since 1.0.0 and is expected to be removed after 12/25/2025."
@@ -297,13 +287,13 @@ def test_deprecate_nested_class_func_since_and_until(warn_caplog_manim):
     )
 
 
-def test_deprecate_nested_func(warn_caplog_manim):
+def test_deprecate_nested_func(manim_caplog):
     """Test the deprecation of a nested method (decorator with no arguments)."""
     b = Top().Bottom()
     answer = b.normal_func()
     answer(1)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The method Top.Bottom.normal_func.<locals>.nested_func has been deprecated and may be removed in a later version."
@@ -311,36 +301,36 @@ def test_deprecate_nested_func(warn_caplog_manim):
     assert answer.__doc__ == f"{doc_admonition}{msg}"
 
 
-def test_deprecate_func_params(warn_caplog_manim):
+def test_deprecate_func_params(manim_caplog):
     """Test the deprecation of method parameters (decorator with params argument)."""
     t = Top()
     t.foo(a=2, b=3, z=4)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameters a and b of method Top.foo have been deprecated and may be removed in a later version. Use something else."
     )
 
 
-def test_deprecate_func_single_param_since_and_until(warn_caplog_manim):
+def test_deprecate_func_single_param_since_and_until(manim_caplog):
     """Test the deprecation of a single method parameter (decorator with since and until arguments)."""
     t = Top()
     t.bar(a=1, b=2)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameter a of method Top.bar has been deprecated since v0.2 and is expected to be removed after v0.4."
     )
 
 
-def test_deprecate_func_param_redirect_tuple(warn_caplog_manim):
+def test_deprecate_func_param_redirect_tuple(manim_caplog):
     """Test the deprecation of a method parameter and redirecting it to a new one using tuple."""
     t = Top()
     obj = t.baz(x=1, old_param=2)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameter old_param of method Top.baz has been deprecated and may be removed in a later version."
@@ -348,12 +338,12 @@ def test_deprecate_func_param_redirect_tuple(warn_caplog_manim):
     assert obj == {"x": 1, "new_param": 2}
 
 
-def test_deprecate_func_param_redirect_lambda(warn_caplog_manim):
+def test_deprecate_func_param_redirect_lambda(manim_caplog):
     """Test the deprecation of a method parameter and redirecting it to a new one using lambda function."""
     t = Top()
     obj = t.qux(runtime_in_ms=500)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameter runtime_in_ms of method Top.qux has been deprecated and may be removed in a later version."
@@ -361,12 +351,12 @@ def test_deprecate_func_param_redirect_lambda(warn_caplog_manim):
     assert obj == {"run_time": 0.5}
 
 
-def test_deprecate_func_param_redirect_many_to_one(warn_caplog_manim):
+def test_deprecate_func_param_redirect_many_to_one(manim_caplog):
     """Test the deprecation of multiple method parameters and redirecting them to one."""
     t = Top()
     obj = t.quux(point2D_x=3, point2D_y=5)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameters point2D_x and point2D_y of method Top.quux have been deprecated and may be removed in a later version."
@@ -374,23 +364,23 @@ def test_deprecate_func_param_redirect_many_to_one(warn_caplog_manim):
     assert obj == {"point2D": (3, 5)}
 
 
-def test_deprecate_func_param_redirect_one_to_many(warn_caplog_manim):
+def test_deprecate_func_param_redirect_one_to_many(manim_caplog):
     """Test the deprecation of one method parameter and redirecting it to many."""
     t = Top()
     obj1 = t.quuz(point2D=0)
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameter point2D of method Top.quuz has been deprecated and may be removed in a later version."
     )
     assert obj1 == {"x": 0, "y": 0}
 
-    warn_caplog_manim.clear()
+    manim_caplog.clear()
 
     obj2 = t.quuz(point2D=(2, 3))
-    assert len(warn_caplog_manim.record_tuples) == 1
-    msg = _get_caplog_record_msg(warn_caplog_manim)
+    assert len(manim_caplog.record_tuples) == 1
+    msg = _get_caplog_record_msg(manim_caplog)
     assert (
         msg
         == "The parameter point2D of method Top.quuz has been deprecated and may be removed in a later version."
diff --git a/tests/test_config.py b/tests/test_config.py
index 6429f1d5cf..649c94351d 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -75,6 +75,18 @@ def test_transparent(config):
     np.testing.assert_allclose(frame[0, 0], [0, 0, 0, 0])
 
 
+def test_transparent_by_background_opacity(config, dry_run):
+    config.background_opacity = 0.5
+    assert config.transparent is True
+
+    scene = MyScene()
+    scene.render()
+    frame = scene.renderer.get_frame()
+    np.testing.assert_allclose(frame[0, 0], [0, 0, 0, 127])
+    assert config.movie_file_extension == ".mov"
+    assert config.transparent is True
+
+
 def test_background_color(config):
     """Test the 'background_color' config option."""