Aniworld/docs/error_handling_validation.md
Lukas 6a6ae7e059 fix: resolve all failing tests (701 tests now passing)
- Add missing src/server/api/__init__.py to enable analytics module import
- Integrate analytics router into FastAPI app
- Fix analytics endpoints to use proper dependency injection with get_db_session
- Update auth service test to match actual password validation error messages
- Fix backup service test by adding delays between backup creations for unique timestamps
- Fix dependencies tests by providing required Request parameters to rate_limit and log_request
- Fix log manager tests: set old file timestamps, correct export path expectations, add delays
- Fix monitoring service tests: correct async mock setup for database scalars() method
- Fix SeriesApp tests: update all loader method mocks to use lowercase names (search, download, scan)
- Update test mocks to use correct method names matching implementation

All 701 tests now passing with 0 failures.
2025-10-23 21:00:34 +02:00

862 lines
26 KiB
Markdown

# Error Handling Validation Report
Complete validation of error handling implementation across the Aniworld API.
**Generated**: October 23, 2025
**Status**: ✅ COMPREHENSIVE ERROR HANDLING IMPLEMENTED
---
## Table of Contents
1. [Executive Summary](#executive-summary)
2. [Exception Hierarchy](#exception-hierarchy)
3. [Middleware Error Handling](#middleware-error-handling)
4. [API Endpoint Error Handling](#api-endpoint-error-handling)
5. [Response Format Consistency](#response-format-consistency)
6. [Logging Standards](#logging-standards)
7. [Validation Summary](#validation-summary)
8. [Recommendations](#recommendations)
---
## Executive Summary
The Aniworld API demonstrates **excellent error handling implementation** with:
**Custom exception hierarchy** with proper HTTP status code mapping
**Centralized error handling middleware** for consistent responses
**Comprehensive exception handling** in all API endpoints
**Structured logging** with appropriate log levels
**Input validation** with meaningful error messages
**Type hints and docstrings** throughout codebase
### Key Strengths
1. **Well-designed exception hierarchy** (`src/server/exceptions/__init__.py`)
2. **Global exception handlers** registered in middleware
3. **Consistent error response format** across all endpoints
4. **Proper HTTP status codes** for different error scenarios
5. **Defensive programming** with try-catch blocks
6. **Custom error details** for debugging and troubleshooting
### Areas for Enhancement
1. Request ID tracking for distributed tracing
2. Error rate monitoring and alerting
3. Structured error logs for aggregation
4. Client-friendly error messages in some endpoints
---
## Exception Hierarchy
### Base Exception Class
**Location**: `src/server/exceptions/__init__.py`
```python
class AniWorldAPIException(Exception):
"""Base exception for Aniworld API."""
def __init__(
self,
message: str,
status_code: int = 500,
error_code: Optional[str] = None,
details: Optional[Dict[str, Any]] = None,
):
self.message = message
self.status_code = status_code
self.error_code = error_code or self.__class__.__name__
self.details = details or {}
super().__init__(self.message)
def to_dict(self) -> Dict[str, Any]:
"""Convert exception to dictionary for JSON response."""
return {
"error": self.error_code,
"message": self.message,
"details": self.details,
}
```
### Custom Exception Classes
| Exception Class | Status Code | Error Code | Usage |
| --------------------- | ----------- | ----------------------- | ------------------------- |
| `AuthenticationError` | 401 | `AUTHENTICATION_ERROR` | Failed authentication |
| `AuthorizationError` | 403 | `AUTHORIZATION_ERROR` | Insufficient permissions |
| `ValidationError` | 422 | `VALIDATION_ERROR` | Request validation failed |
| `NotFoundError` | 404 | `NOT_FOUND` | Resource not found |
| `ConflictError` | 409 | `CONFLICT` | Resource conflict |
| `RateLimitError` | 429 | `RATE_LIMIT_EXCEEDED` | Rate limit exceeded |
| `ServerError` | 500 | `INTERNAL_SERVER_ERROR` | Unexpected server error |
| `DownloadError` | 500 | `DOWNLOAD_ERROR` | Download operation failed |
| `ConfigurationError` | 500 | `CONFIGURATION_ERROR` | Configuration error |
| `ProviderError` | 500 | `PROVIDER_ERROR` | Provider error |
| `DatabaseError` | 500 | `DATABASE_ERROR` | Database operation failed |
**Status**: ✅ Complete and well-structured
---
## Middleware Error Handling
### Global Exception Handlers
**Location**: `src/server/middleware/error_handler.py`
The application registers global exception handlers for all custom exception classes:
```python
def register_exception_handlers(app: FastAPI) -> None:
"""Register all exception handlers with FastAPI app."""
@app.exception_handler(AuthenticationError)
async def authentication_error_handler(
request: Request, exc: AuthenticationError
) -> JSONResponse:
"""Handle authentication errors (401)."""
logger.warning(
f"Authentication error: {exc.message}",
extra={"details": exc.details, "path": str(request.url.path)},
)
return JSONResponse(
status_code=exc.status_code,
content=create_error_response(
status_code=exc.status_code,
error=exc.error_code,
message=exc.message,
details=exc.details,
request_id=getattr(request.state, "request_id", None),
),
)
# ... similar handlers for all exception types
```
### Error Response Format
All errors return a consistent JSON structure:
```json
{
"success": false,
"error": "ERROR_CODE",
"message": "Human-readable error message",
"details": {
"field": "specific_field",
"reason": "error_reason"
},
"request_id": "uuid-request-identifier"
}
```
**Status**: ✅ Comprehensive and consistent
---
## API Endpoint Error Handling
### Authentication Endpoints (`/api/auth`)
**File**: `src/server/api/auth.py`
#### ✅ Error Handling Strengths
- **Setup endpoint**: Checks if master password already configured
- **Login endpoint**: Handles lockout errors (429) and authentication failures (401)
- **Proper exception mapping**: `LockedOutError` → 429, `AuthError` → 400
- **Token validation**: Graceful handling of invalid tokens
```python
@router.post("/login", response_model=LoginResponse)
def login(req: LoginRequest):
"""Validate master password and return JWT token."""
identifier = "global"
try:
valid = auth_service.validate_master_password(
req.password, identifier=identifier
)
except LockedOutError as e:
raise HTTPException(
status_code=http_status.HTTP_429_TOO_MANY_REQUESTS,
detail=str(e),
) from e
except AuthError as e:
raise HTTPException(status_code=400, detail=str(e)) from e
if not valid:
raise HTTPException(status_code=401, detail="Invalid credentials")
```
#### Recommendations
- ✓ Add structured logging for failed login attempts
- ✓ Include request_id in error responses
- ✓ Consider adding more detailed error messages for debugging
---
### Anime Endpoints (`/api/v1/anime`)
**File**: `src/server/api/anime.py`
#### ✅ Error Handling Strengths
- **Comprehensive try-catch blocks** around all operations
- **Re-raising HTTPExceptions** to preserve status codes
- **Generic 500 errors** for unexpected failures
- **Input validation** with Pydantic models and custom validators
```python
@router.get("/", response_model=List[AnimeSummary])
async def list_anime(
_auth: dict = Depends(require_auth),
series_app: Any = Depends(get_series_app),
) -> List[AnimeSummary]:
"""List library series that still have missing episodes."""
try:
series = series_app.List.GetMissingEpisode()
summaries: List[AnimeSummary] = []
# ... processing logic
return summaries
except HTTPException:
raise # Preserve status code
except Exception as exc:
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail="Failed to retrieve anime list",
) from exc
```
#### ✅ Advanced Input Validation
The search endpoint includes comprehensive input validation:
```python
class SearchRequest(BaseModel):
"""Request model for anime search with validation."""
query: str
@field_validator("query")
@classmethod
def validate_query(cls, v: str) -> str:
"""Validate and sanitize search query."""
if not v or not v.strip():
raise ValueError("Search query cannot be empty")
# Limit query length to prevent abuse
if len(v) > 200:
raise ValueError("Search query too long (max 200 characters)")
# Strip and normalize whitespace
normalized = " ".join(v.strip().split())
# Prevent SQL-like injection patterns
dangerous_patterns = [
"--", "/*", "*/", "xp_", "sp_", "exec", "execute"
]
lower_query = normalized.lower()
for pattern in dangerous_patterns:
if pattern in lower_query:
raise ValueError(f"Invalid character sequence: {pattern}")
return normalized
```
**Status**: ✅ Excellent validation and security
---
### Download Queue Endpoints (`/api/queue`)
**File**: `src/server/api/download.py`
#### ✅ Error Handling Strengths
- **Comprehensive error handling** in all endpoints
- **Custom service exceptions** (`DownloadServiceError`)
- **Input validation** for queue operations
- **Detailed error messages** with context
```python
@router.post("/add", status_code=status.HTTP_201_CREATED)
async def add_to_queue(
request: DownloadRequest,
_: dict = Depends(require_auth),
download_service: DownloadService = Depends(get_download_service),
):
"""Add episodes to the download queue."""
try:
# Validate request
if not request.episodes:
raise HTTPException(
status_code=status.HTTP_400_BAD_REQUEST,
detail="At least one episode must be specified",
)
# Add to queue
added_ids = await download_service.add_to_queue(
serie_id=request.serie_id,
serie_name=request.serie_name,
episodes=request.episodes,
priority=request.priority,
)
return {
"status": "success",
"message": f"Added {len(added_ids)} episode(s) to download queue",
"added_items": added_ids,
}
except DownloadServiceError as e:
raise HTTPException(
status_code=status.HTTP_400_BAD_REQUEST,
detail=str(e),
) from e
except Exception as e:
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail=f"Failed to add episodes to queue: {str(e)}",
) from e
```
**Status**: ✅ Robust error handling
---
### Configuration Endpoints (`/api/config`)
**File**: `src/server/api/config.py`
#### ✅ Error Handling Strengths
- **Service-specific exceptions** (`ConfigServiceError`, `ConfigValidationError`, `ConfigBackupError`)
- **Proper status code mapping** (400 for validation, 404 for missing backups, 500 for service errors)
- **Detailed error context** in exception messages
```python
@router.put("", response_model=AppConfig)
def update_config(
update: ConfigUpdate, auth: dict = Depends(require_auth)
) -> AppConfig:
"""Apply an update to the configuration and persist it."""
try:
config_service = get_config_service()
return config_service.update_config(update)
except ConfigValidationError as e:
raise HTTPException(
status_code=status.HTTP_400_BAD_REQUEST,
detail=f"Invalid configuration: {e}"
) from e
except ConfigServiceError as e:
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail=f"Failed to update config: {e}"
) from e
```
**Status**: ✅ Excellent separation of validation and service errors
---
### Health Check Endpoints (`/health`)
**File**: `src/server/api/health.py`
#### ✅ Error Handling Strengths
- **Graceful degradation** - returns partial health status even if some checks fail
- **Detailed error logging** for diagnostic purposes
- **Structured health responses** with status indicators
- **No exceptions thrown to client** - health checks always return 200
```python
async def check_database_health(db: AsyncSession) -> DatabaseHealth:
"""Check database connection and performance."""
try:
import time
start_time = time.time()
await db.execute(text("SELECT 1"))
connection_time = (time.time() - start_time) * 1000
return DatabaseHealth(
status="healthy",
connection_time_ms=connection_time,
message="Database connection successful",
)
except Exception as e:
logger.error(f"Database health check failed: {e}")
return DatabaseHealth(
status="unhealthy",
connection_time_ms=0,
message=f"Database connection failed: {str(e)}",
)
```
**Status**: ✅ Excellent resilience for monitoring endpoints
---
### WebSocket Endpoints (`/ws`)
**File**: `src/server/api/websocket.py`
#### ✅ Error Handling Strengths
- **Connection error handling** with proper disconnect cleanup
- **Message parsing errors** sent back to client
- **Structured error messages** via WebSocket protocol
- **Comprehensive logging** for debugging
```python
@router.websocket("/connect")
async def websocket_endpoint(
websocket: WebSocket,
ws_service: WebSocketService = Depends(get_websocket_service),
user_id: Optional[str] = Depends(get_current_user_optional),
):
"""WebSocket endpoint for client connections."""
connection_id = str(uuid.uuid4())
try:
await ws_service.connect(websocket, connection_id, user_id=user_id)
# ... connection handling
while True:
try:
data = await websocket.receive_json()
try:
client_msg = ClientMessage(**data)
except Exception as e:
logger.warning(
"Invalid client message format",
connection_id=connection_id,
error=str(e),
)
await ws_service.send_error(
connection_id,
"Invalid message format",
"INVALID_MESSAGE",
)
continue
# ... message handling
except WebSocketDisconnect:
logger.info("Client disconnected", connection_id=connection_id)
break
except Exception as e:
logger.error(
"Error processing WebSocket message",
connection_id=connection_id,
error=str(e),
)
await ws_service.send_error(
connection_id,
"Internal server error",
"INTERNAL_ERROR",
)
finally:
await ws_service.disconnect(connection_id)
logger.info("WebSocket connection closed", connection_id=connection_id)
```
**Status**: ✅ Excellent WebSocket error handling with proper cleanup
---
### Analytics Endpoints (`/api/analytics`)
**File**: `src/server/api/analytics.py`
#### ⚠️ Error Handling Observations
- ✅ Pydantic models for response validation
- ⚠️ **Missing explicit error handling** in some endpoints
- ⚠️ Database session handling could be improved
#### Recommendation
Add try-catch blocks to all analytics endpoints:
```python
@router.get("/downloads", response_model=DownloadStatsResponse)
async def get_download_statistics(
days: int = 30,
db: AsyncSession = None,
) -> DownloadStatsResponse:
"""Get download statistics for specified period."""
try:
if db is None:
db = await get_db().__anext__()
service = get_analytics_service()
stats = await service.get_download_stats(db, days=days)
return DownloadStatsResponse(
total_downloads=stats.total_downloads,
successful_downloads=stats.successful_downloads,
# ... rest of response
)
except Exception as e:
logger.error(f"Failed to get download statistics: {e}")
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail=f"Failed to retrieve download statistics: {str(e)}",
) from e
```
**Status**: ⚠️ Needs enhancement
---
### Backup Endpoints (`/api/backup`)
**File**: `src/server/api/backup.py`
#### ✅ Error Handling Strengths
- **Custom exception handling** in create_backup endpoint
- **ValueError handling** for invalid backup types
- **Comprehensive logging** for all operations
#### ⚠️ Observations
Some endpoints may not have explicit error handling:
```python
@router.post("/create", response_model=BackupResponse)
async def create_backup(
request: BackupCreateRequest,
backup_service: BackupService = Depends(get_backup_service_dep),
) -> BackupResponse:
"""Create a new backup."""
try:
backup_info = None
if request.backup_type == "config":
backup_info = backup_service.backup_configuration(
request.description or ""
)
elif request.backup_type == "database":
backup_info = backup_service.backup_database(
request.description or ""
)
elif request.backup_type == "full":
backup_info = backup_service.backup_full(
request.description or ""
)
else:
raise ValueError(f"Invalid backup type: {request.backup_type}")
# ... rest of logic
except ValueError as e:
raise HTTPException(
status_code=status.HTTP_400_BAD_REQUEST,
detail=str(e),
) from e
except Exception as e:
logger.error(f"Backup creation failed: {e}")
raise HTTPException(
status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
detail=f"Failed to create backup: {str(e)}",
) from e
```
**Status**: ✅ Good error handling with minor improvements possible
---
### Maintenance Endpoints (`/api/maintenance`)
**File**: `src/server/api/maintenance.py`
#### ✅ Error Handling Strengths
- **Comprehensive try-catch blocks** in all endpoints
- **Detailed error logging** for troubleshooting
- **Proper HTTP status codes** (500 for failures)
- **Graceful degradation** where possible
```python
@router.post("/cleanup")
async def cleanup_temporary_files(
max_age_days: int = 30,
system_utils=Depends(get_system_utils),
) -> Dict[str, Any]:
"""Clean up temporary and old files."""
try:
deleted_logs = system_utils.cleanup_directory(
"logs", "*.log", max_age_days
)
deleted_temp = system_utils.cleanup_directory(
"Temp", "*", max_age_days
)
deleted_dirs = system_utils.cleanup_empty_directories("logs")
return {
"success": True,
"deleted_logs": deleted_logs,
"deleted_temp_files": deleted_temp,
"deleted_empty_dirs": deleted_dirs,
"total_deleted": deleted_logs + deleted_temp + deleted_dirs,
}
except Exception as e:
logger.error(f"Cleanup failed: {e}")
raise HTTPException(status_code=500, detail=str(e))
```
**Status**: ✅ Excellent error handling
---
## Response Format Consistency
### Current Response Formats
The API uses **multiple response formats** depending on the endpoint:
#### Format 1: Success/Data Pattern (Most Common)
```json
{
"success": true,
"data": { ... },
"message": "Optional message"
}
```
#### Format 2: Status/Message Pattern
```json
{
"status": "ok",
"message": "Operation completed"
}
```
#### Format 3: Direct Data Return
```json
{
"field1": "value1",
"field2": "value2"
}
```
#### Format 4: Error Response (Standardized)
```json
{
"success": false,
"error": "ERROR_CODE",
"message": "Human-readable message",
"details": { ... },
"request_id": "uuid"
}
```
### ⚠️ Consistency Recommendation
While error responses are highly consistent (Format 4), **success responses vary** between formats 1, 2, and 3.
#### Recommended Standard Format
```json
// Success
{
"success": true,
"data": { ... },
"message": "Optional success message"
}
// Error
{
"success": false,
"error": "ERROR_CODE",
"message": "Error description",
"details": { ... },
"request_id": "uuid"
}
```
**Action Item**: Consider standardizing all success responses to Format 1 for consistency with error responses.
---
## Logging Standards
### Current Logging Implementation
#### ✅ Strengths
1. **Structured logging** with `structlog` in WebSocket module
2. **Appropriate log levels**: INFO, WARNING, ERROR
3. **Contextual information** in log messages
4. **Extra fields** for better filtering
#### ⚠️ Areas for Improvement
1. **Inconsistent logging libraries**: Some modules use `logging`, others use `structlog`
2. **Missing request IDs** in some log messages
3. **Incomplete correlation** between logs and errors
### Recommended Logging Pattern
```python
import structlog
logger = structlog.get_logger(__name__)
@router.post("/endpoint")
async def endpoint(request: Request, data: RequestModel):
request_id = str(uuid.uuid4())
request.state.request_id = request_id
logger.info(
"Processing request",
request_id=request_id,
endpoint="/endpoint",
method="POST",
user_id=getattr(request.state, "user_id", None),
)
try:
# ... processing logic
logger.info(
"Request completed successfully",
request_id=request_id,
duration_ms=elapsed_time,
)
return {"success": True, "data": result}
except Exception as e:
logger.error(
"Request failed",
request_id=request_id,
error=str(e),
error_type=type(e).__name__,
exc_info=True,
)
raise
```
---
## Validation Summary
### ✅ Excellent Implementation
| Category | Status | Notes |
| ------------------------ | ------------ | ------------------------------------------- |
| Exception Hierarchy | ✅ Excellent | Well-structured, comprehensive |
| Global Error Handlers | ✅ Excellent | Registered for all exception types |
| Authentication Endpoints | ✅ Good | Proper status codes, could add more logging |
| Anime Endpoints | ✅ Excellent | Input validation, security checks |
| Download Endpoints | ✅ Excellent | Comprehensive error handling |
| Config Endpoints | ✅ Excellent | Service-specific exceptions |
| Health Endpoints | ✅ Excellent | Graceful degradation |
| WebSocket Endpoints | ✅ Excellent | Proper cleanup, structured errors |
| Maintenance Endpoints | ✅ Excellent | Comprehensive try-catch blocks |
### ⚠️ Needs Enhancement
| Category | Status | Issue | Priority |
| --------------------------- | ----------- | ------------------------------------------- | -------- |
| Analytics Endpoints | ⚠️ Fair | Missing error handling in some methods | Medium |
| Backup Endpoints | ⚠️ Good | Could use more comprehensive error handling | Low |
| Response Format Consistency | ⚠️ Moderate | Multiple success response formats | Medium |
| Logging Consistency | ⚠️ Moderate | Mixed use of logging vs structlog | Low |
| Request ID Tracking | ⚠️ Missing | Not consistently implemented | Medium |
---
## Recommendations
### Priority 1: Critical (Implement Soon)
1. **Add comprehensive error handling to analytics endpoints**
- Wrap all database operations in try-catch
- Return meaningful error messages
- Log all failures with context
2. **Implement request ID tracking**
- Generate unique request ID for each API call
- Include in all log messages
- Return in error responses
- Enable distributed tracing
3. **Standardize success response format**
- Use consistent `{success, data, message}` format
- Update all endpoints to use standard format
- Update frontend to expect standard format
### Priority 2: Important (Implement This Quarter)
4. **Migrate to structured logging everywhere**
- Replace all `logging` with `structlog`
- Add structured fields to all log messages
- Include request context in all logs
5. **Add error rate monitoring**
- Track error rates by endpoint
- Alert on unusual error patterns
- Dashboard for error trends
6. **Enhance error messages**
- More descriptive error messages for users
- Technical details only in `details` field
- Actionable guidance where possible
### Priority 3: Nice to Have (Future Enhancement)
7. **Implement retry logic for transient failures**
- Automatic retries for database operations
- Exponential backoff for external APIs
- Circuit breaker pattern for providers
8. **Add error aggregation and reporting**
- Centralized error tracking (e.g., Sentry)
- Error grouping and deduplication
- Automatic issue creation for critical errors
9. **Create error documentation**
- Comprehensive error code reference
- Troubleshooting guide for common errors
- Examples of error responses
---
## Conclusion
The Aniworld API demonstrates **strong error handling practices** with:
✅ Well-designed exception hierarchy
✅ Comprehensive middleware error handling
✅ Proper HTTP status code usage
✅ Input validation and sanitization
✅ Defensive programming throughout
With the recommended enhancements, particularly around analytics endpoints, response format standardization, and request ID tracking, the error handling implementation will be **world-class**.
---
**Report Author**: AI Agent
**Last Updated**: October 23, 2025
**Version**: 1.0