Issue #18743 has been updated by marcper (Marcelo Pereira).
Hello @ko1, let me know if the patch in the current form is acceptable.
Best,
Marcelo
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Bug #18743: Enumerator#next / peek re-use each others stacktraces
https://bugs.ruby-lang.org/issues/18743#change-102602
* Author: sos4nt (Stefan Schüßler)
* Status: Open
* Priority: Normal
* Assignee: ko1 (Koichi Sasada)
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
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I encountered an odd behavior.
If I rescue the `StopIteration` exception from `peek` and call `next` afterwards: (or
vice-versa)
```ruby
# enum.rb # 1
# 2
enum = [].each # 3
enum.peek rescue nil # 4
enum.next # 5
```
it will show the stacktrace from the rescued `peek` call:
```
$ ruby enum.rb
enum.rb:4:in `peek': iteration reached an end (StopIteration)
from enum.rb:4:in `<main>'
```
Whereas the error should refer to `next` on line number 5.
The same happens when calling `peek` after `next` or when having muliple `peek` / `next`
calls:
```ruby
# enum.rb # 1
# 2
enum = [].each # 3
enum.peek rescue nil # 4
enum.next rescue nil # 5
enum.peek rescue nil # 6
puts "line #{__LINE__}" # 7
enum.next # 8
```
The stacktrace from the first (rescued) `peek` or `next` call will be shown which
doesn't reflect the actual error location:
```
$ ruby enum.rb
line 7
enum.rb:4:in `peek': iteration reached an end (StopIteration)
from enum.rb:4:in `<main>'
```
This is very confusing when debugging code.
---Files--------------------------------
01-Recreate-stacktrace-enumerator.patch (1.29 KB)
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