ai-agent-book 精选快照（<2MB 代码与文档，来自 github.com/bojieli/ai-agent-book）

chapter4/perception-tools/test_video_keyframes_num_frames.py

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+"""Regression test: num_frames=0 must not cause ZeroDivisionError.
+
+The LLM-supplied num_frames parameter was used directly as a divisor in
+`frame_count // num_frames`; num_frames=0 crashed with ZeroDivisionError
+(surfacing as a confusing tool error). It is now clamped to >= 1 up front.
+"""
+import asyncio
+import json
+import os
+import sys
+import types
+from types import SimpleNamespace
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "src"))
+
+# Optional runtime deps for importing the chapter module in unit tests.
+sys.modules.setdefault("dotenv", types.SimpleNamespace(load_dotenv=lambda: None))
+mcp = types.ModuleType("mcp")
+mcp_types = types.ModuleType("mcp.types")
+
+
+class TextContent:
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)
+
+
+mcp_types.TextContent = TextContent
+sys.modules["mcp"] = mcp
+sys.modules["mcp.types"] = mcp_types
+
+import cv2
+import numpy as np
+
+import media_processing_tools
+from media_processing_tools import extract_video_keyframes
+
+
+def _make_clip(path, frames=20):
+    fourcc = cv2.VideoWriter_fourcc(*"mp4v")
+    out = cv2.VideoWriter(str(path), fourcc, 10.0, (64, 48))
+    for _ in range(frames):
+        out.write(np.zeros((48, 64, 3), dtype=np.uint8))
+    out.release()
+
+
+def test_extract_keyframes_zero_num_frames_is_clamped(tmp_path):
+    clip = tmp_path / "clip.mp4"
+    _make_clip(clip)
+    result = asyncio.run(extract_video_keyframes(str(clip), num_frames=0))
+    payload = json.loads(result.text)
+    assert payload["success"] is True
+    assert "division" not in str(payload["message"]).lower()
+
+
+def test_analyze_video_ai_zero_num_frames_is_clamped(tmp_path, monkeypatch):
+    clip = tmp_path / "clip.mp4"
+    _make_clip(clip)
+
+    message = SimpleNamespace(content="a frame")
+    response = SimpleNamespace(choices=[SimpleNamespace(message=message)])
+    client = SimpleNamespace(chat=SimpleNamespace(
+        completions=SimpleNamespace(create=lambda **kwargs: response)))
+    monkeypatch.setattr(media_processing_tools, "_make_vision_client",
+                        lambda: (client, "fake-model"))
+
+    result = asyncio.run(media_processing_tools.analyze_video_ai(str(clip), num_frames=0))
+    payload = json.loads(result.text)
+    assert payload["success"] is True
+    assert "division" not in str(payload["message"]).lower()