Issue #8398 has been reported by goshakkk (Gosha Arinich).

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Bug #8398: case/when shouldn't try to evaluate all AND joined conditions if one of preceding was falsy 
https://bugs.ruby-lang.org/issues/8398

Author: goshakkk (Gosha Arinich)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: 1.9.3, 2.0.0
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


=begin

Steps to reproduce:

 case 1
 when String && proc { |x| x.blah }
   :something
 else
   :no
 end

Here is how I thought it works: goes to the first 'when', evals the first condition ((({1 === String}))), sees it's false and proceeds to the next (({when})) (or (({else}))) and happily returns (({:no})).

As it turns out, even if one of AND joined conditions was false, ruby would still try to eval other conditions, and as soon as it calls the block with 1, (({NoMethodError})) gets thrown as there is no (({#blah})) on Integer.

I believe this is incorrect behavior and conditions with AND in case/when should behave like everywhere else.

=end



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