CODEWITHSUNDEEP
ruby
Harikrishnan R
Harikrishnan R

Reputation: 1454

class function is not included from module

Trying to inject my own function (say check) to Float class. When I am doing from a module it is not injected to Float class. Please see the following snippets. 

irb(main):001:0> module QA
irb(main):002:1>   class Float
irb(main):003:2>     def self.check
irb(main):004:3>     end
irb(main):005:2>   end
irb(main):006:1> end
=> nil
irb(main):007:0> include QA
=> Object
irb(main):008:0> Float.respond_to?(:check)
=> false
irb(main):009:0> extend QA
=> main
irb(main):010:0> Float.respond_to?(:check)
=> false
irb(main):011:0> class Float
irb(main):012:1>   def self.check
irb(main):013:2>   end
irb(main):014:1> end
=> nil
irb(main):015:0> Float.respond_to?(:check)
=> true

Upvotes: 1

Views: 72

Answers (2)

Jörg W Mittag
Jörg W Mittag

Reputation: 369458

You have added the method to the QA::Float class, not the Float class. If you want to add the method to the Float class, you should do

module QA
  class ::Float
    # stuff
  end
end

Or even better just

class Float
  # stuff
end

Upvotes: 2

mu is too short
mu is too short

Reputation: 434665

This:

module QA
  class Float
    def self.check
    end
  end
end

Is creating/modifying the class QA::Float, not Float. Try doing

QA::Float.respond_to?(:check)

And you'll see.

You could do something like this instead:

module QA
    def self.included(klass)
        Float.class_eval "def self.check;end"
    end
end

include QA
Float.respond_to?(:check)
# true

Some useful references:

Upvotes: 2

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