From: "ioquatix (Samuel Williams)" Date: 2021-08-18T23:04:36+00:00 Subject: [ruby-core:104980] [Ruby master Feature#18083] Capture error in ensure block. Issue #18083 has been updated by ioquatix (Samuel Williams). There are lots of ways to achieve this but the reality is there is a lot of code which uses `$!` in the ensure block which is incorrect for the reasons already explained. Your proposed ideas are fine, except that RuboCop will warn you against `rescue Exception`. I agree with the general sentiment around this. That being said, there are definitely valid use cases where your ensure block wants to know whether it's exiting via a normal code flow or an exceptional one. To answer your question, `ensure => error`, error would be the equivalent of a local `$!`, so nothing really changes, we are just providing a mechanism to do correctly and safely what people are already doing with `$!`. ---------------------------------------- Feature #18083: Capture error in ensure block. https://bugs.ruby-lang.org/issues/18083#change-93380 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal ---------------------------------------- As discussed in https://bugs.ruby-lang.org/issues/15567 there are some tricky edge cases. As a general model, something like the following would be incredibly useful: ``` ruby begin ... ensure => error pp "error occurred" if error end ``` Currently you can get similar behaviour like this: ``` ruby begin ... rescue Exception => error raise ensure pp "error occurred" if error end ``` The limitation of this approach is it only works if you don't need any other `rescue` clause. Otherwise, it may not work as expected or require extra care. Also, Rubocop will complain about it. Using `$!` can be buggy if you call some method from `rescue` or `ensure` clause, since it would be set already. It was discussed extensively in https://bugs.ruby-lang.org/issues/15567 if you want more details. -- https://bugs.ruby-lang.org/ Unsubscribe: