Add comprehensive tests for formatter classes, services, and utilities

- Introduced tests for various formatter classes including TextFormatter, DurationFormatter, SizeFormatter, DateFormatter, and more to ensure correct formatting behavior.
- Added tests for service classes such as FileTreeService, MetadataService, and RenameService, covering directory validation, metadata extraction, and file renaming functionalities.
- Implemented utility tests for LanguageCodeExtractor, PatternExtractor, and FrameClassMatcher to validate their extraction and matching capabilities.
- Updated test cases to use datasets for better maintainability and clarity.
- Enhanced error handling tests to ensure robustness against missing or invalid data.

renamer/test/conftest.py

@@ -1,6 +1,9 @@
 # conftest.py - pytest configuration
 import os
 import sys
+import json
+import pytest
+from pathlib import Path
 
 # Force UTF-8 encoding for all I/O operations
 os.environ['PYTHONIOENCODING'] = 'utf-8'
@@ -12,4 +15,77 @@ if hasattr(sys.stderr, 'reconfigure'):
 # Configure pytest to handle Unicode properly
 def pytest_configure(config):
     # Ensure UTF-8 encoding for test output
-    config.option.capture = 'no'  # Don't capture output to avoid encoding issues
+    config.option.capture = 'no'  # Don't capture output to avoid encoding issues
+
+
+# Dataset loading helpers
+@pytest.fixture
+def datasets_dir():
+    """Get the datasets directory path."""
+    return Path(__file__).parent / "datasets"
+
+
+@pytest.fixture
+def load_filename_patterns(datasets_dir):
+    """Load filename pattern test cases from JSON dataset.
+
+    Returns:
+        list: List of test case dictionaries with 'filename' and 'expected' keys
+    """
+    dataset_file = datasets_dir / "filenames" / "filename_patterns.json"
+    with open(dataset_file, 'r', encoding='utf-8') as f:
+        data = json.load(f)
+    return data['test_cases']
+
+
+@pytest.fixture
+def load_frame_class_tests(datasets_dir):
+    """Load frame class test cases from JSON dataset.
+
+    Returns:
+        list: List of frame class test dictionaries
+    """
+    dataset_file = datasets_dir / "mediainfo" / "frame_class_tests.json"
+    with open(dataset_file, 'r', encoding='utf-8') as f:
+        return json.load(f)
+
+
+def load_dataset(dataset_name: str) -> dict:
+    """Load a dataset by name.
+
+    Args:
+        dataset_name: Name of the dataset file (without .json extension)
+
+    Returns:
+        dict: Loaded dataset
+
+    Example:
+        >>> data = load_dataset('filename_patterns')
+        >>> test_cases = data['test_cases']
+    """
+    datasets_dir = Path(__file__).parent / "datasets"
+
+    # Search for the dataset in subdirectories
+    for subdir in ['filenames', 'mediainfo', 'expected_results']:
+        dataset_file = datasets_dir / subdir / f"{dataset_name}.json"
+        if dataset_file.exists():
+            with open(dataset_file, 'r', encoding='utf-8') as f:
+                return json.load(f)
+
+    raise FileNotFoundError(f"Dataset '{dataset_name}' not found in datasets directory")
+
+
+def get_test_file_path(filename: str) -> Path:
+    """Get path to a test file in the datasets directory.
+
+    Args:
+        filename: Name of the test file
+
+    Returns:
+        Path: Full path to the test file
+
+    Example:
+        >>> path = get_test_file_path('test.mkv')
+        >>> # Returns: /path/to/test/datasets/sample_mediafiles/test.mkv
+    """
+    return Path(__file__).parent / "datasets" / "sample_mediafiles" / filename