fix: keep optional ImageMagick demo import-safe

.github/workflows/tests.yml

@@ -34,4 +34,4 @@ jobs:
           python -m pip check
 
       - name: Test runtime, installation, and CLI help
-        run: python -m pytest -q tests/test_gradio_runtime_compat.py tests/test_installation_docs.py tests/test_cli_stage_help.py
+        run: python -m pytest -q tests/test_gradio_runtime_compat.py tests/test_installation_docs.py tests/test_cli_stage_help.py tests/test_demo_import.py

funclip/test/imagemagick_test.py

@@ -1,18 +1,21 @@
-from moviepy.editor import *
-from moviepy.video.tools.subtitles import SubtitlesClip, TextClip
-from moviepy.editor import VideoFileClip, concatenate_videoclips
-from moviepy.video.compositing import CompositeVideoClip
+"""Optional media demo; importing this module must not render a video."""
 
-generator = lambda txt: TextClip(txt, font='./font/STHeitiMedium.ttc', fontsize=48, color='white')
-subs = [((0, 2), 'sub1中文字幕'),
-        ((2, 4), 'subs2'),
-        ((4, 6), 'subs3'),
-        ((6, 8), 'subs4')]
+if __name__ == "__main__":
+    from moviepy.editor import *
+    from moviepy.video.tools.subtitles import SubtitlesClip, TextClip
+    from moviepy.editor import VideoFileClip, concatenate_videoclips
+    from moviepy.video.compositing import CompositeVideoClip
 
-subtitles = SubtitlesClip(subs, generator)
+    generator = lambda txt: TextClip(txt, font='./font/STHeitiMedium.ttc', fontsize=48, color='white')
+    subs = [((0, 2), 'sub1中文字幕'),
+            ((2, 4), 'subs2'),
+            ((4, 6), 'subs3'),
+            ((6, 8), 'subs4')]
 
-video = VideoFileClip("examples/2022云栖大会_片段.mp4.mp4")
-video = video.subclip(0, 8)
-video = CompositeVideoClip([video, subtitles.set_pos(('center','bottom'))])
+    subtitles = SubtitlesClip(subs, generator)
 
-video.write_videofile("test_output.mp4")
+    video = VideoFileClip("examples/2022云栖大会_片段.mp4.mp4")
+    video = video.subclip(0, 8)
+    video = CompositeVideoClip([video, subtitles.set_pos(('center','bottom'))])
+
+    video.write_videofile("test_output.mp4")

tests/test_demo_import.py

@@ -0,0 +1,29 @@
+"""Optional media demos must not run while tools import or collect them."""
+
+from pathlib import Path
+import subprocess
+import sys
+
+
+def test_imagemagick_demo_import_is_side_effect_free(tmp_path):
+    demo = Path(__file__).resolve().parents[1] / "funclip/test/imagemagick_test.py"
+    code = """
+import importlib.util
+import sys
+
+spec = importlib.util.spec_from_file_location("funclip_imagemagick_demo", sys.argv[1])
+module = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(module)
+"""
+    result = subprocess.run(
+        [sys.executable, "-I", "-S", "-c", code, str(demo)],
+        cwd=tmp_path,
+        capture_output=True,
+        text=True,
+        timeout=20,
+    )
+
+    assert result.returncode == 0, result.stderr
+    assert result.stdout == ""
+    assert result.stderr == ""
+    assert list(tmp_path.iterdir()) == []