New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

#to_ary behavior does not conform to MRI Ruby (1.7.22) #3378

Closed
asthasr opened this Issue Oct 8, 2015 · 1 comment

Comments

Projects
None yet
2 participants
@asthasr

asthasr commented Oct 8, 2015

In MRI Ruby, when you iterate over an object providing a block with extra parameters, it seems that #to_ary is called and, if it returns nil, is disregarded. This is a test that you can execute to see the behavior on different Rubies:

class Example
  def to_ary
    nil
  end
end

test = [Example.new].map { |x, _| x }

puts test == [nil] ? "fail" : "pass"

On MRI versions, this passes. On JRuby 1.7.22, it returns [nil] and thus fails. On JRuby 9.0.1.0, it raises an exception: TypeError: Example#to_ary should return Array. It seems that the behavior in this case should conform to the behavior on MRI, in order to avoid surprising behavior when attempting to use map, each and other enumerable methods.

In real projects, this is observable on any ActiveRecord object as well as DelayedJob, as seen in Issue #3338.

Note -- I am opening this bug for 1.7.22 per a request from @enebo .

@enebo

This comment has been minimized.

Show comment
Hide comment
@enebo

enebo Oct 8, 2015

Member

commit noted for this in #3338.

Member

enebo commented Oct 8, 2015

commit noted for this in #3338.

@enebo enebo closed this Oct 8, 2015

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment