Add unit tests for MediaInfo frame class detection

- Created a JSON file containing various test cases for different video resolutions and their expected frame classes.
- Implemented a pytest test script that loads the test cases and verifies the frame class detection functionality of the MediaInfoExtractor.
- Utilized mocking to simulate the behavior of the MediaInfoExtractor and its video track attributes.

renamer/test/test_mediainfo_extractor.py

@@ -1,6 +1,7 @@
 import pytest
 from pathlib import Path
 from renamer.extractors.mediainfo_extractor import MediaInfoExtractor
+import json
 
 
 class TestMediaInfoExtractor:
@@ -13,6 +14,13 @@ class TestMediaInfoExtractor:
         """Use the filenames.txt file for testing"""
         return Path(__file__).parent / "filenames.txt"
 
+    @pytest.fixture
+    def frame_class_cases(self):
+        """Load test cases for frame class extraction"""
+        cases_file = Path(__file__).parent / "test_mediainfo_frame_class_cases.json"
+        with open(cases_file, 'r') as f:
+            return json.load(f)
+
     def test_extract_resolution(self, extractor, test_file):
         """Test extracting resolution from media info"""
         resolution = extractor.extract_resolution()
@@ -47,4 +55,22 @@ class TestMediaInfoExtractor:
         """Test checking if video is 3D"""
         is_3d = extractor.is_3d()
         # Text files don't have video tracks
-        assert is_3d is False
+        assert is_3d is False
+
+    @pytest.mark.parametrize("case", [
+        pytest.param(case, id=case["testname"]) 
+        for case in json.load(open(Path(__file__).parent / "test_mediainfo_frame_class_cases.json"))
+    ])
+    def test_extract_frame_class(self, case):
+        """Test extracting frame class from various resolutions"""
+        # Create a mock extractor with the test resolution
+        extractor = MediaInfoExtractor.__new__(MediaInfoExtractor)
+        extractor.video_tracks = [{
+            'width': case["resolution"][0],
+            'height': case["resolution"][1],
+            'interlaced': 'Yes' if case["interlaced"] else None
+        }]
+        
+        result = extractor.extract_frame_class()
+        print(f"Case: {case['testname']}, resolution: {case['resolution']}, expected: {case['expected_frame_class']}, got: {result}")
+        assert result == case["expected_frame_class"], f"Failed for {case['testname']}: expected {case['expected_frame_class']}, got {result}"