Bug in Performance/Count

[bquorning]

With this file test.rb:

# encoding: utf-8

# nodoc #
class A < Array
  def count(&block)
    select(&block).count
  end
end

a = A.new
a += [1, 2, 3, 4, 5, 6]
p a.count { |e| e > 1 }

RuboCop tells me that An error occurred while Performance/Count cop was inspecting /Users/bquorning/Code/rubocop/test.rb.

Extra information:

0.32.1 (using Parser 2.2.2.5, running on ruby 2.2.2 x86_64-darwin13)

Actually, I was using the latest master, cdfb667.

[bquorning]

cc @rrosenblum

[rrosenblum]

I will look into this.

[rrosenblum]

I have a fix for this. I will put in a pull request shortly.

In the given example, the auto correct would be incorrect because of the method name.

def count(&block)
  select(&block).count
end

would correct to

def count(&block)
  count(&block)
end

which would be a recursive call and not function properly. To fix the code, the method would need to be renamed, the method should be removed, or the method should call super(&block).

For the fix, I am not taking into consideration that the defined method name is going to be the same as the correction.

[bquorning]

For the fix, I am not taking into consideration that the defined method name is going to be the same as the correction.

Fine by me 👍