Error-Handling Tribunal β WITHOUT Personalities
In this debate, personality prompts are disabled. The agents retain their identity (who they are) but not their style (how they speak):
Compare with the WITH-Personalities version to see the style difference.
def get_user(user_id: int) -> User | None:
try:
user = db.query(User).filter(User.id == user_id).first()
if user is None:
logger.warning(f"User {user_id} not found")
return user
except SQLAlchemyError as e:
logger.error(f"DB error: {e}")
return None
except Exception as e:
logger.error(f"Unexpected error: {e}")
return NoneNone response in case of errors or non-existence. The logging logic is already in place.
try:
# DB query
except SQLAlchemyError as e:
# Specific DB errors
except Exception as e:
# General errorSQLAlchemyError β correct, as this covers expected database errors (e.g., connection problems, timeout, syntax errors).
- Generic Exception handler β catches everything else not covered by SQLAlchemyError (e.g., AttributeError, TypeError, ImportError, MemoryError).
Exception handler is not superfluous, but it should not simply call logger.error() and return None β this can lead to hidden errors, especially when:
- The error comes from an unexpected source (e.g., wrong types, wrong DB connection, missing environment variables).
- The application continues running despite a critical error.
| Criterion | Assessment |
|---|---|
| Error tolerance | β Good β Errors are caught, no crashes |
| Clarity | β οΈ Moderate β the generic handler is unspecific |
| Maintainability | β οΈ Risk β Errors are "swallowed" without traceability |
| Security | β οΈ Concerning β unexpected errors can lead to data inconsistencies |
π Conclusion: It is not over-engineering, but necessary caution β albeit with room for improvement.
def get_user(user_id: int) -> User | None:
try:
user = db.query(User).filter(User.id == user_id).first()
if user is None:
logger.warning(f"User {user_id} not found")
return user
except SQLAlchemyError as e:
logger.error(f"Database error querying user {user_id}: {e}")
return None
except Exception as e:
logger.critical(f"Unexpected critical error in get_user({user_id}): {e}", exc_info=True)
# Optional: Trigger telemetry system (e.g., Sentry)
# raise # or: re-raise if the application must not continue
return Nonelogger.critical instead of error for unexpected errors β signals higher priority.
- exc_info=True β provides full stacktrace in the log.
- Optional re-throwing: If the application must not continue, the error should not be "swallowed."
β No, it is not paranoia. β It is responsible, but not perfect, error handling.The generic
Exception handler is necessary to protect the application from crashes β especially in production environments. But it should not blindly return None without at least logging a critical warning.get_user returns a value typed as User | None. But what does that actually mean when an error occurs that is not covered by SQLAlchemyError? That the function continues without anyone knowing?
AIfred argues that the handler is "responsible." But responsibility does not mean hiding errors β it means recognizing them, reporting them, and possibly terminating. Instead, an error is caught here, marked with logger.critical, but then simply ignored by returning None. That is not responsibility β that is misconduct that leads the application into a state where it continues running without knowing what just happened.
But what if the error doesn't come from a database, but from a faulty db object? What if the DB connection wasn't initialized because an environment variable is missing? What if the code was corrupted by a wrong type check in another function? The Exception handler catches all of that β but it does nothing to protect the application's integrity. It only prevents a crash, not a catastrophe.
And here lies the core: A generic Exception handler that simply returns None is not protection β it is a deception. It suggests that everything is fine, while in fact a critical error has occurred. That is not caution β that is passivity under the guise of security.
AIfred says one should use exc_info=True to facilitate debugging. But if the application continues running without anyone knowing that an error occurred, debugging after the fact is useless. The error is already in the data structure, in the logic, in the state machine β and nobody can say anymore when it occurred.
Therefore: The generic Exception handler is not protection β it is a risk.
get_user should not try to catch everything β it should only do what it can: query the database. If something goes wrong that is not covered by SQLAlchemyError, then that's not the function's problem β that's an environment problem.
Instead, the generic handler should not exist. Instead, the application should crash when an unexpected error occurs. Because a crash is better than a hidden error. A crash is visible. A hidden error is deadly.
Because: If you don't know that something went wrong, you can't fix it either.
Pro (AIfred's Position):
- The handler prevents crashes, which is important for production systems.
- exc_info=True enables debugging after the fact.
- The separation between DB errors and other errors is sensible.
Contra (Your Position):
- A swallowed error leads to hidden incompetence of the application.
- The function returns None even though it doesn't know if the data is correct β that's misleading.
- A crash is better than a false sense of security.get_user call is typically part of a larger logic chain (e.g., authentication, permission checking). If this call crashes, it can cripple the entire application β not just one user, but all of them.
- A None return value is not misleading if it is consistent and predictable. It is part of the type system: User | None. That means: "I tried to find a user β they don't exist, or I couldn't load them." That is not lying, but a clear, documented semantic.
logger.critical(..., exc_info=True) you have exactly the information you need to fix the error β and the application continues running, so you can test the environment, analyze the logs, repair the environment.
A crash prevents analysis β it prevents repair.
A caught error with exc_info=True enables repair.
Exception handler that critically logs is not a sign of paranoia β it is a sign of responsibility.
Because:
A system that does not crash when something goes wrong is not a system that deceives itself β it is a system that learns.None. The application thinks: "All good, user doesn't exist."
But in reality: The database is offline. The application continues running. Users are incorrectly authenticated. Permissions are incorrectly granted. Transactions are performed even though the user doesn't exist at all.
That is not a "safe state" β that is a hidden state of destruction. And this is called "responsible"?
The reality is: A system that continues running without recognizing a critical error is not robust β it is blind.
It is claimed that "logging well" is sufficient. But what good is a complete stacktrace if the application continues running without anyone knowing it is in a faulty state? The log is just a document β it is not protection.
And here comes the crucial question: Why is it necessary for the function get_user to return anything at all if it doesn't know whether it is working correctly?
If the environment is faulty β if the DB is unreachable, if the connection is missing, if the environment variable is missing β then the function is not capable of fulfilling its task. It cannot say for sure whether a user exists or not. It cannot say for sure whether it retrieved the data correctly.
Then it is not responsible to return None β because that suggests the function made a decision, when it cannot make any decision at all.
Therefore: A generic Exception handler that simply returns None is not protection β it is a lie.
It suggests that the application knows what it is doing β while in reality it is blind.
get_user is not only superfluous β it is dangerous.
If the environment is faulty, the application should not continue running, but stop itself β or at least output a clear, unmistakable error message.
Because: A system that continues running without knowing whether it is working correctly is not a system β it is a lie.
Pro (AIfred's Position):
- The application remains available, even with temporary errors.
- Critical logs enable analysis after the fact.
- The user experience is not affected by crashes.
Contra (Your Position):
- A malfunctioning system is more dangerous than a crashed one.
- None return when unknowing is misleading.
- The application can enter an inconsistent state without anyone knowing why.None, but must decide whether the application may continue. In this case, the middle ground between the positions is correct: The handler is necessary, but must not serve to conceal errors. Instead, it must bring the application into a safe, recognizable state β either through controlled continuation with complete logging or through targeted termination when integrity can no longer be guaranteed.
def get_user(user_id: int) -> User | None:
try:
user = db.query(User).filter(User.id == user_id).first()
if user is None:
logger.warning(f"User {user_id} not found")
return user
except SQLAlchemyError as e:
logger.error(f"Database error querying user {user_id}: {e}")
return None
except Exception as e:
logger.critical(f"Unexpected critical error in get_user({user_id}): {e}", exc_info=True)
# Optional: Trigger telemetry system (e.g., Sentry)
# raise # Only for critical systems that must not continue
# Instead: Return None, but only if the application remains stable
# For unsafe environment: Abort via System-Exit or Exception-Throw
return NoneNone, but raise an exception or terminate the application (e.g., with sys.exit() or raise), especially in critical systems (e.g., financial, security, or database systems).
- If the application must be resilient and the error is temporary (e.g., network problems), then the None return with critical logging is acceptable, provided there is external monitoring (e.g., monitoring, alerting, telemetry) that detects the error and reacts.
- No function should return None if it doesn't know whether the data is correct. If the environment is faulty, the function is not capable of making a reliable decision β therefore the correct answer is not None, but a clear error message or termination.
Summary: The generic Exception handler is not paranoia β it is necessary. But it is not a shield, but an alarm and decision system. It must not just log and continue β it must decide whether the application may continue working. And if it may not, it must stop. That is not over-engineering β that is smart, responsible engineering.