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/fill_sample_mediafiles.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+"""
+Script to generate empty media test files from filename_patterns.json dataset.
+
+Usage:
+    uv run python renamer/test/fill_sample_mediafiles.py
+
+This script:
+1. Creates the sample_mediafiles directory if it doesn't exist
+2. Generates empty files for all filenames in filename_patterns.json
+3. Reports statistics on files created
+
+The sample_mediafiles directory should be added to .gitignore as these are
+generated files used only for testing file system operations.
+"""
+
+import json
+from pathlib import Path
+
+
+def create_sample_mediafiles():
+    """Create empty media files from filename_patterns.json dataset."""
+
+    # Load filename patterns dataset
+    dataset_file = Path(__file__).parent / 'datasets' / 'filenames' / 'filename_patterns.json'
+
+    if not dataset_file.exists():
+        print(f"❌ Error: Dataset file not found: {dataset_file}")
+        return False
+
+    with open(dataset_file, 'r', encoding='utf-8') as f:
+        data = json.load(f)
+
+    # Create sample_mediafiles directory
+    mediafiles_dir = Path(__file__).parent / 'datasets' / 'sample_mediafiles'
+    mediafiles_dir.mkdir(parents=True, exist_ok=True)
+
+    print(f"Creating sample media files in: {mediafiles_dir}")
+    print(f"Test cases in dataset: {len(data['test_cases'])}")
+    print()
+
+    # Create empty files
+    created = 0
+    skipped = 0
+    errors = []
+
+    for case in data['test_cases']:
+        filename = case['filename']
+        filepath = mediafiles_dir / filename
+
+        try:
+            if filepath.exists():
+                skipped += 1
+            else:
+                # Create empty file
+                filepath.touch()
+                created += 1
+                print(f"  ✅ Created: {filename}")
+        except Exception as e:
+            errors.append((filename, str(e)))
+            print(f"  ❌ Error creating {filename}: {e}")
+
+    # Summary
+    print()
+    print("=" * 70)
+    print("Summary:")
+    print(f"  Created: {created} files")
+    print(f"  Skipped (already exist): {skipped} files")
+    print(f"  Errors: {len(errors)} files")
+    print(f"  Total in dataset: {len(data['test_cases'])} files")
+    print()
+
+    if errors:
+        print("Errors encountered:")
+        for filename, error in errors:
+            print(f"  - {filename}: {error}")
+        print()
+
+    # Check for files in directory not in dataset
+    all_files = {f.name for f in mediafiles_dir.glob('*') if f.is_file()}
+    dataset_files = {case['filename'] for case in data['test_cases']}
+    extra_files = all_files - dataset_files
+
+    if extra_files:
+        print(f"⚠️  Warning: {len(extra_files)} files in directory not in dataset:")
+        for f in sorted(extra_files):
+            print(f"  - {f}")
+        print()
+
+    print("✅ Sample media files generation complete!")
+    print()
+    print("Next steps:")
+    print("1. Add 'renamer/test/datasets/sample_mediafiles/' to .gitignore")
+    print("2. Run tests to verify files are accessible")
+
+    return True
+
+
+if __name__ == '__main__':
+    import sys
+    success = create_sample_mediafiles()
+    sys.exit(0 if success else 1)