Be specific with exceptions

Avoid catching broad exception types like `Exception` and instead catch specific exceptions that you expect and can handle appropriately. When errors occur, they should be explicit rather than failing silently, and should include proper logging or re-raising when necessary.

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Prompt

Reviewer Prompt
Deploy Agent

Avoid catching broad exception types like Exception and instead catch specific exceptions that you expect and can handle appropriately. When errors occur, they should be explicit rather than failing silently, and should include proper logging or re-raising when necessary.

Key principles:

  • Catch specific exception types rather than using broad except Exception: clauses
  • Don’t let failures happen silently - add logging or explicit error handling
  • Re-raise exceptions when you can’t handle them properly
  • Be explicit about what can fail and why

Example of what to avoid:

try:
    last_parameters_msg.liveParameters.stiffnessFactor = last_parameters_dict['stiffnessFactor']
    params_reader.put("LiveParameters", last_parameters_msg.to_bytes())
except Exception:  # Too broad, fails silently
    pass

Better approach:

try:
    last_parameters_msg.liveParameters.stiffnessFactor = last_parameters_dict['stiffnessFactor']
    params_reader.put("LiveParameters", last_parameters_msg.to_bytes())
except (json.JSONDecodeError, KeyError) as e:  # Specific exceptions
    cloudlog.warn(f"Failed to migrate cached params: {e}")

This approach makes code more maintainable by clearly documenting what can go wrong and ensuring failures are visible rather than hidden.

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