# Edge Case and Error Handling Tests Summary
This document summarizes the four edge case and error handling test files created for the document processing system.
## Test Files Created
### 1. test_malformed_documents.py
**Purpose**: Test handling of malformed documents across different file types.
**Key Test Cases**:
- Empty documents (Markdown, plaintext, Python, JavaScript)
- Malformed YAML frontmatter (unclosed, invalid syntax, invalid characters)
- Incomplete Markdown structures (unclosed code blocks, malformed tables, broken links)
- Python files with syntax errors (missing colons, unmatched brackets, invalid indentation)
- JavaScript files with syntax errors
- Binary content in text files
- Extremely long lines (25k+ characters)
- Circular references in documents
- Mixed character encodings
- Malformed nested structures (deeply nested lists, nested blockquotes)
- Search functionality on malformed documents
**Error Handling**: Tests verify that the system can process documents even when they contain errors, extracting what information it can while handling errors gracefully.
### 2. test_document_edge_cases.py
**Purpose**: Test various edge cases in document processing.
**Key Test Cases**:
- Zero-byte files
- Single character files
- Files containing only whitespace (spaces, tabs, newlines, non-breaking spaces)
- Extreme nesting levels (deeply nested headings and lists)
- Unusual file extensions (.markdown, .mdown, .mkd, .mdx)
- Files without extensions (README, LICENSE)
- Extremely long identifiers/names (1000+ characters)
- Rapid content changes (simulating real-time editing)
- Various line ending styles (LF, CRLF, CR, mixed)
- Chunk boundary edge cases
- Metadata extraction edge cases
- Concurrent indexing of the same file
- Special Markdown elements (HTML comments, collapsible sections, custom containers)
- Performance with many small chunks
- Search with special characters
**Error Handling**: Tests ensure the system handles unusual but valid inputs correctly.
### 3. test_unicode_documents.py
**Purpose**: Test Unicode handling across different document types.
**Key Test Cases**:
- Basic Unicode characters (emojis, math symbols, Greek letters, accented characters)
- Asian characters (Japanese, Chinese, Korean)
- Unicode in code files (identifiers, comments, strings)
- Unicode normalization forms (NFC vs NFD)
- Unicode in identifiers (where supported)
- Right-to-left text (Arabic, Hebrew)
- Zero-width characters
- Combining characters
- Surrogate pairs
- Variation selectors
- Unicode in URLs and file paths
- Unicode search queries
- Unicode file names
- Byte Order Mark (BOM) handling
- Control characters
- Various Unicode categories (currency, math operators, arrows, etc.)
**Error Handling**: Tests verify proper Unicode handling without data corruption or crashes.
### 4. test_document_error_recovery.py
**Purpose**: Test error recovery mechanisms in document processing.
**Key Test Cases**:
- Parser error recovery
- Memory error recovery (simulated)
- Encoding error recovery
- Concurrent access recovery
- Partial chunk failure recovery
- Metadata extraction failure recovery
- File system error recovery
- Infinite recursion prevention
- Timeout recovery
- Malformed AST recovery
- Resource cleanup on error
- Partial semantic index failure
- Search error recovery
- Graceful degradation when features fail
**Error Handling**: Tests focus on ensuring the system can recover from various error conditions and continue operating.
## Key Principles Tested
1. **Graceful Degradation**: When something fails, the system should extract what it can rather than failing completely.
2. **Error Isolation**: Errors in one part of processing shouldn't affect other parts.
3. **Data Preservation**: Even malformed input should be processed to extract any valid information.
4. **Performance**: Edge cases shouldn't cause performance degradation or hangs.
5. **Unicode Safety**: All text processing should handle the full range of Unicode correctly.
6. **Concurrent Safety**: Multiple operations on the same resources should be handled safely.
## Running the Tests
Each test file can be run individually:
```bash
pytest test_malformed_documents.py -v
pytest test_document_edge_cases.py -v
pytest test_unicode_documents.py -v
pytest test_document_error_recovery.py -v
```
Or run all edge case tests:
```bash
pytest test_*documents*.py -v
```
## Note on Implementation
The tests revealed that the current implementation needs some adjustments:
- Plugin initialization requires proper configuration objects
- The storage layer methods differ from what was expected
- Some plugins always return at least a document symbol even for empty files
A simplified test file `test_malformed_documents_simple.py` was also created that demonstrates the core concepts with proper error handling.
