Issue #19197 has been updated by rubyFeedback (mark potter). I do not have any particular opinion on the issue as such, but on the issue of object.cause.cause.cause (object.method1.method1.method1). From an API point of view I think this is normally not "the ruby way" when it leads to repetition. Usually ruby favours being expressive in what one does, e. g. collection.take(10) or .first(20) or .last(30). If I understand it correctly you prefer more control over the error report? If so then I think that makes sense; mame improved on the error feedback ruby gives, if I recall correctly. I now get a lot more information about where an error happens, including a follow-up trace. I don't remember this in the ruby 1.8.x era, for instance. ---------------------------------------- Feature #19197: Add Exception#root_cause https://bugs.ruby-lang.org/issues/19197#change-101806 * Author: AMomchilov (Alexander Momchilov) * Status: Open * Priority: Normal ---------------------------------------- ### Description I would like to add a `#root_cause` method to `Exception`. It returns the last exception in linked-list of causality chain, that is, the original exception (whose own `cause` is `nil`). ### Example ```ruby e = begin raise 'a' # This is the root cause rescue => a begin raise 'b' rescue => b begin raise 'c' # This is the outermost cause assigned to `e` rescue => c c end end end p(e) # => #<RuntimeError: c> p(e.cause) # => #<RuntimeError: b> p(e.cause.cause) # => #<RuntimeError: a> p(e.cause.cause.cause) # => nil p(e.root_cause) # => #<RuntimeError: a> p(e.root_cause.cause) # => nil ``` ### Motivation There are some kinds of exceptions that can occur all over the place (and might be wrapped by arbitrarily many middlemen), but are attributable to a singular global cause. For example, a database outage could raise exceptions in almost every line of business logic of an app that uses ActiveRecord models. Fundamentally, you wouldn't want an error report for every one of these lines. You'd want to look at the root cause, and bucket all SQL-connection issues into a single report, regardless of where they surface. ### Implementation Draft PR: https://github.com/ruby/ruby/pull/6913 -- https://bugs.ruby-lang.org/

Issue #19197 has been updated by AMomchilov (Alexander Momchilov). Hey Robert, thanks for taking the time to write. rubyFeedback (robert heiler) wrote in #note-2: Ah, I wasn't suggesting to use this style of code, it was just a very simple/concise demonstration of the structure of the sample exception I made. I've updated my post to clarify that. rubyFeedback (robert heiler) wrote in #note-2: Correct! rubyFeedback (robert heiler) wrote in #note-2: Sorry, I don't understand what you're trying to say here ---------------------------------------- Feature #19197: Add Exception#root_cause https://bugs.ruby-lang.org/issues/19197#change-101853 * Author: AMomchilov (Alexander Momchilov) * Status: Open * Priority: Normal ---------------------------------------- ### Description I would like to add a `#root_cause` method to `Exception`. It returns the last exception in linked-list of causality chain, that is, the original exception (whose own `cause` is `nil`). ### Example ```ruby e = begin raise 'A' # This is the root cause rescue => a begin raise 'B' rescue => B begin raise 'C' # This is the outermost cause assigned to `e` rescue => c c end end end # Here's what the structure looks like: # C -> B -> A -> nil p(e) # => #<RuntimeError: C> p(e.cause) # => #<RuntimeError: B> p(e.cause.cause) # => #<RuntimeError: A> p(e.cause.cause.cause) # => nil # Here's the proposed API, showing that A is the root cause of e p(e.root_cause) # => #<RuntimeError: A> # And that the root_cause has no further cause p(e.root_cause.cause) # => nil ``` ### Motivation There are some kinds of exceptions that can occur all over the place (and might be wrapped by arbitrarily many middlemen), but are attributable to a singular global cause. For example, a database outage could raise exceptions in almost every line of business logic of an app that uses ActiveRecord models. Fundamentally, you wouldn't want an error report for every one of these lines. You'd want to look at the root cause, and bucket all SQL-connection issues into a single report, regardless of where they surface. ### Implementation Draft PR: https://github.com/ruby/ruby/pull/6913 -- https://bugs.ruby-lang.org/

Issue #19197 has been updated by Eregon (Benoit Daloze). I think more complex cases like `causes` should be done manually or with a helper method, like you showed or with some loop or something. OTOH I think `root_cause` is convenient and useful for a variety of cases, so it makes more sense to be in core. ---------------------------------------- Feature #19197: Add Exception#root_cause https://bugs.ruby-lang.org/issues/19197#change-101871 * Author: AMomchilov (Alexander Momchilov) * Status: Open * Priority: Normal ---------------------------------------- ### Description I would like to add a `#root_cause` method to `Exception`. It returns the last exception in linked-list of causality chain, that is, the original exception (whose own `cause` is `nil`). ### Example ```ruby e = begin raise 'A' # This is the root cause rescue => a begin raise 'B' rescue => B begin raise 'C' # This is the outermost cause assigned to `e` rescue => c c end end end # Here's what the structure looks like: # C -> B -> A -> nil p(e) # => #<RuntimeError: C> p(e.cause) # => #<RuntimeError: B> p(e.cause.cause) # => #<RuntimeError: A> p(e.cause.cause.cause) # => nil # Here's the proposed API, showing that A is the root cause of e p(e.root_cause) # => #<RuntimeError: A> # And that the root_cause has no further cause p(e.root_cause.cause) # => nil ``` ### Motivation There are some kinds of exceptions that can occur all over the place (and might be wrapped by arbitrarily many middlemen), but are attributable to a singular global cause. For example, a database outage could raise exceptions in almost every line of business logic of an app that uses ActiveRecord models. Fundamentally, you wouldn't want an error report for every one of these lines. You'd want to look at the root cause, and bucket all SQL-connection issues into a single report, regardless of where they surface. ### Implementation Draft PR: https://github.com/ruby/ruby/pull/6913 -- https://bugs.ruby-lang.org/

Issue #19197 has been updated by AMomchilov (Alexander Momchilov). mame (Yusuke Endoh) wrote in #note-8: I was experimenting around in an IRB session with some code that raised an exception wrapped by another exception. Actually getting to the root cause is pretty cumbersome. In a REPL environment, the best you can do is `Enumerator.produce(e) { |e| e.cause or raise StopIteration }.to_a.last`, which is still a handfull. In our case it was Bugsnag. They do already have an API to let you decide how to group things by any arbitrary value. We wanted to group some things by root causes, and to do that we needed to iterate these error linked lists ourselves to get those ourselves. Yep, and I did I write the Ruby code to get the root cause, and that's fine, but it just felt like a pretty basic (albeit niche) thing that should be built in. ---------------------------------------- Feature #19197: Add Exception#root_cause https://bugs.ruby-lang.org/issues/19197#change-103390 * Author: AMomchilov (Alexander Momchilov) * Status: Open * Priority: Normal ---------------------------------------- ### Description I would like to add a `#root_cause` method to `Exception`. It returns the last exception in linked-list of causality chain, that is, the original exception (whose own `cause` is `nil`). ### Example ```ruby e = begin raise 'A' # This is the root cause rescue => a begin raise 'B' rescue => B begin raise 'C' # This is the outermost cause assigned to `e` rescue => c c end end end # Here's what the structure looks like: # C -> B -> A -> nil p(e) # => #<RuntimeError: C> p(e.cause) # => #<RuntimeError: B> p(e.cause.cause) # => #<RuntimeError: A> p(e.cause.cause.cause) # => nil # Here's the proposed API, showing that A is the root cause of e p(e.root_cause) # => #<RuntimeError: A> # And that the root_cause has no further cause p(e.root_cause.cause) # => nil ``` ### Motivation There are some kinds of exceptions that can occur all over the place (and might be wrapped by arbitrarily many middlemen), but are attributable to a singular global cause. For example, a database outage could raise exceptions in almost every line of business logic of an app that uses ActiveRecord models. Fundamentally, you wouldn't want an error report for every one of these lines. You'd want to look at the root cause, and bucket all SQL-connection issues into a single report, regardless of where they surface. ### Implementation Draft PR: https://github.com/ruby/ruby/pull/6913 -- https://bugs.ruby-lang.org/