Documentation: middleware / errorHandler
Purpose:
Catches errors, logs them, and renders error pages or messages.
Lifecycle Role:
Final middleware in chain; handles errors from all prior middleware.
Dependencies:
Upstream:
all routes and middleware
Downstream:
none
Data Flow:
Inputs:
Error objects from previous middleware
Outputs:
HTTP error responses with rendered error pages
Side Effects:
Logs errors to console or persistent logs
Performance and Scalability:
Bottlenecks:
- Overly generic error messages
- Missing stack trace logging in production
Concurrency:
None
Security and Stability:
Validation:
Sanitizes error output to avoid sensitive info leakage
Vulnerabilities:
- Potential info leakage if error messages expose internals
Architecture Assessment:
Coupling:
Last middleware, no downstream Dependencies
Abstraction:
Centralized error handling abstraction
Recommendations:
- Log errors persistently with context
- Customize error messages to balance info and security