Refine seller store implementation

server/tests/test_video_renderer.py

@@ -0,0 +1,26 @@
+"""轮播视频的无 FFmpeg 依赖单测：时长策略是 API/前端说明的共同契约。"""
+from __future__ import annotations
+
+import sys
+import unittest
+from pathlib import Path
+
+SERVER_DIR = Path(__file__).resolve().parents[1]
+if str(SERVER_DIR) not in sys.path:
+    sys.path.insert(0, str(SERVER_DIR))
+
+from services.video_renderer import VideoRenderError, slide_seconds_for
+
+
+class SlideDurationTests(unittest.TestCase):
+    def test_duration_strategy_for_two_to_five_images(self) -> None:
+        self.assertEqual([slide_seconds_for(count) for count in range(2, 6)], [4.5, 3.5, 3.0, 2.8])
+
+    def test_rejects_unsupported_count(self) -> None:
+        for count in (0, 1, 6):
+            with self.subTest(count=count), self.assertRaises(VideoRenderError):
+                slide_seconds_for(count)
+
+
+if __name__ == "__main__":
+    unittest.main()