test: add tests for scene description generator

tests/test_scene_descriptions.py

@@ -0,0 +1,167 @@
+#!/usr/bin/env python3
+"""
+Tests for generate_scene_descriptions.py
+
+Tests the scene description generation pipeline including:
+- Media file scanning
+- Model detection
+- JSON parsing from vision responses
+- Output format validation
+
+Ref: timmy-config#689
+"""
+
+import json
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+# Add scripts to path for import
+import sys
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "scripts"))
+
+from generate_scene_descriptions import (
+    IMAGE_EXTS,
+    VIDEO_EXTS,
+    ALL_EXTS,
+    VISION_MODELS,
+    auto_detect_model,
+    check_model_available,
+    scan_media,
+    extract_video_frame,
+)
+
+
+class TestMediaScanning(unittest.TestCase):
+    """Test media file scanning."""
+
+    def test_scan_empty_directory(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            result = scan_media(tmpdir)
+            self.assertEqual(result, [])
+
+    def test_scan_nonexistent_directory(self):
+        result = scan_media("/nonexistent/path/that/does/not/exist")
+        self.assertEqual(result, [])
+
+    def test_scan_with_images(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            # Create test files
+            for ext in [".jpg", ".png", ".webp"]:
+                (Path(tmpdir) / f"test{ext}").touch()
+
+            result = scan_media(tmpdir)
+            self.assertEqual(len(result), 3)
+
+    def test_scan_recursive(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            subdir = Path(tmpdir) / "sub" / "dir"
+            subdir.mkdir(parents=True)
+            (subdir / "deep.jpg").touch()
+            (Path(tmpdir) / "top.png").touch()
+
+            result = scan_media(tmpdir)
+            self.assertEqual(len(result), 2)
+
+    def test_scan_ignores_unsupported(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            (Path(tmpdir) / "image.jpg").touch()
+            (Path(tmpdir) / "document.pdf").touch()
+            (Path(tmpdir) / "script.py").touch()
+
+            result = scan_media(tmpdir)
+            self.assertEqual(len(result), 1)
+
+    def test_scan_sorted_output(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            for name in ["z.jpg", "a.png", "m.webp"]:
+                (Path(tmpdir) / name).touch()
+
+            result = scan_media(tmpdir)
+            names = [p.name for p in result]
+            self.assertEqual(names, sorted(names))
+
+
+class TestModelDetection(unittest.TestCase):
+    """Test model availability detection."""
+
+    @patch('generate_scene_descriptions.urllib.request.urlopen')
+    def test_check_model_available(self, mock_urlopen):
+        mock_resp = MagicMock()
+        mock_resp.read.return_value = json.dumps({
+            "models": [{"name": "gemma4:latest"}]
+        }).encode()
+        mock_urlopen.return_value.__enter__ = MagicMock(return_value=mock_resp)
+        mock_urlopen.return_value.__exit__ = MagicMock(return_value=False)
+        mock_urlopen.return_value = mock_resp
+
+        result = check_model_available("gemma4:latest")
+        self.assertTrue(result)
+
+    @patch('generate_scene_descriptions.urllib.request.urlopen')
+    def test_check_model_not_available(self, mock_urlopen):
+        mock_resp = MagicMock()
+        mock_resp.read.return_value = json.dumps({
+            "models": [{"name": "llama2:7b"}]
+        }).encode()
+        mock_urlopen.return_value = mock_resp
+
+        result = check_model_available("gemma4:latest")
+        self.assertFalse(result)
+
+    @patch('generate_scene_descriptions.check_model_available')
+    def test_auto_detect_prefers_gemma4(self, mock_check):
+        def side_effect(model, url):
+            return model == "gemma4:latest"
+        mock_check.side_effect = side_effect
+
+        result = auto_detect_model()
+        self.assertEqual(result, "gemma4:latest")
+
+    @patch('generate_scene_descriptions.check_model_available')
+    def test_auto_detect_falls_back(self, mock_check):
+        def side_effect(model, url):
+            return model == "llava:latest"
+        mock_check.side_effect = side_effect
+
+        result = auto_detect_model()
+        self.assertEqual(result, "llava:latest")
+
+    @patch('generate_scene_descriptions.check_model_available')
+    def test_auto_detect_returns_none_when_no_models(self, mock_check):
+        mock_check.return_value = False
+        result = auto_detect_model()
+        self.assertIsNone(result)
+
+
+class TestConstants(unittest.TestCase):
+    """Test constant definitions."""
+
+    def test_image_extensions(self):
+        self.assertIn(".jpg", IMAGE_EXTS)
+        self.assertIn(".png", IMAGE_EXTS)
+        self.assertIn(".webp", IMAGE_EXTS)
+
+    def test_video_extensions(self):
+        self.assertIn(".mp4", VIDEO_EXTS)
+        self.assertIn(".webm", VIDEO_EXTS)
+
+    def test_all_extensions_union(self):
+        self.assertEqual(ALL_EXTS, IMAGE_EXTS | VIDEO_EXTS)
+
+    def test_vision_models_ordered(self):
+        self.assertEqual(VISION_MODELS[0], "gemma4:latest")
+        self.assertIn("llava:latest", VISION_MODELS)
+
+
+class TestVideoFrameExtraction(unittest.TestCase):
+    """Test video frame extraction."""
+
+    def test_extract_nonexistent_video(self):
+        result = extract_video_frame(Path("/nonexistent.mp4"), Path("/tmp/frame.jpg"))
+        self.assertFalse(result)
+
+
+if __name__ == "__main__":
+    unittest.main()