58 Matching Annotations
  1. Aug 2023
    1. The question is also not about error handling and if the file write fails, exiting with a stack trace is reasonable default behavior because there's not much you can do to recover from that.
  2. Jul 2023
    1. You might want to suppress only ValueError, since a TypeError (the input was not a string or numeric value) might indicate a legitimate bug in your program. To do that, write the exception type after except: def attempt_float(x): try: return float(x) except ValueError: return x
  3. Nov 2022
    1. I just spent a day dismantling a model, trying to find the cause of the silent rollback - taking out every association, every validation, every callback, whittling down all the code in the transaction, only to finally discover that it was return true that was the cause of it all. Or yes, an exception!
  4. Sep 2022
    1. This code is much easier to understand as it do not add levels of indentation and follows the principle where the 0 indentation level is the principal path of the application where other paths are exceptions or rare cases.
    1. Otherwise behaves according to the value of null_value_treatment which must be one of 'raise_exception', 'use_json_null', 'delete_key', or 'return_target'. The default is 'use_json_null'.
  5. Jan 2022
  6. Apr 2021
  7. Mar 2021
  8. Feb 2021
    1. the ability to “error out” when something goes wrong
    2. If anything here did fail in “validate omniauth”, all other steps in the chain would be skipped as the flow would follow the path leading to the failure terminus.
    3. Things could go wrong in two places here. First, the validation could fail if Github sends us data we don’t understand. Second, we might not know the user signing in, meaning the “find user” logic has to error-out
    1. Return None. That’s evil too! You either will end up with if something is not None: on almost every line and global pollution of your logic by type-checking conditionals, or will suffer from TypeError every day. Not a pleasant choice.
    2. we also wrap them in Failure to solve the second problem: spotting potential exceptions is hard
    3. So, the sad conclusion is: all problems must be resolved individually depending on a specific usage context. There’s no silver bullet to resolve all ZeroDivisionErrors once and for all. And again, I am not even covering complex IO flows with retry policies and expotential timeouts.
    1. Monads provide an elegant way of handling errors, exceptions and chaining functions so that the code is much more understandable and has all the error handling, without all the ifs and elses.
    1. Maybe T can be understood as a "wrapping" type, wrapping the type T into a new type with built-in exception handling
    2. Undefined values or operations are one particular problem that robust software should prepare for and handle gracefully.
    1. Other filters will ignore blocks when given to them.

      Would be better to raise an error if block isn't allowed/expected!

    2. Note that it's perfectly fine to add errors during execution. Not all errors have to come from type checking or validation.
    3. Inside the interaction, we could use #find instead of #find_by_id. That way we wouldn't need the #find_account! helper method in the controller because the error would bubble all the way up. However, you should try to avoid raising errors from interactions. If you do, you'll have to deal with raised exceptions as well as the validity of the outcome.

      What they're referring to:

      Account.find('invalid') will raise an error but Account.find_by(id: 'invalid') will not.

  9. Dec 2020
    1. the best way to ensure you've handled all errors in your run() function is to use run().catch(). In other words, handle errors when calling the function as opposed to handling each individual error.
    2. // The `.then(v => [null, v], err => [err, null])` pattern // lets you use array destructuring to get both the error and // the result
  10. Nov 2020
  11. Sep 2020
  12. Jul 2020
    1. JSON parsing is always pain in ass. If the input is not as expected it throws an error and crashes what you are doing. You can use the following tiny function to safely parse your input. It always turns an object even if the input is not valid or is already an object which is better for most cases.

      It would be nicer if the parse method provided an option to do it safely and always fall back to returning an object instead of raising exception if it couldn't parse the input.

  13. May 2020
  14. developer.mozilla.org developer.mozilla.org
    1. in the absence of an immediate need, it is simpler to leave out error handling until a final .catch() statement.
    2. Handling a rejected promise too early has consequences further down the promise chain.   Sometimes there is no choice, because an error must be handled immediately.
  15. Apr 2020
  16. Mar 2020
    1. To be just a bit polemic, your first instinct was not to do that. And you probably wouldn't think of that in your unit tests either (the holy grail of dynamic langs). So someday it would blow up at runtime, and THEN you'd add that safeguard.
    2. I want to raise errors with more context
    3. As many would guess: ... catch StandardError => e raise $! ... raises the same error referenced by $!, the same as simply calling: ... catch StandardError => e raise ... but probably not for the reasons one might think. In this case, the call to raise is NOT just raising the object in $!...it raises the result of $!.exception(nil), which in this case happens to be $!.
    1. It is recommended that a library should have one subclass of StandardError or RuntimeError and have specific exception types inherit from it. This allows the user to rescue a generic exception type to catch all exceptions the library may raise even if future versions of the library add new exception subclasses.
    1. The pattern below has become exceptionally useful for me (pun intended). It's clean, can be easily modularized, and the errors are expressive. Within my class I define new errors that inherit from StandardError, and I raise them with messages (for example, the object associated with the error).
  17. Dec 2019
  18. Mar 2019
    1. Você consegue visualizar a saúde da sua aplicação?

      Ainda que aqui os tópicos da certificação não cubram exatamente esse assunto, monitorar a saúde de um sistema e suas aplicações é missão do profissional DevOps. Atente para os tópicos:

      701 Software Engineering 701.1 Modern Software Development (weight: 6)

      e

      705.2 Log Management and Analysis (weight: 4)