Clone and patch class in ruby-CodePudding

I need to create pathed copy of the class, where calls to one module method are replaced to another module method calls:

module Foo
    def self.check
        "foo"
    end
end

module Bar
    def self.check
        "bar"
    end
end

class Bark
    def call
        puts Foo.check
    end
end

Bark.new.call => "foo"

Meouw = Bark.dup

...

???

Meouw.new.call => "bar"

Any ideas how would i achieve that?

CodePudding user response：

Not an answer to the question as it was asked, but in my opinion you are trying to solve an XY problem and this is not the way to go.

What you need to do is to inject the dependency instead of hardcoding it.

module Foo
  def self.check
    "foo"
  end
end

module Bar
  def self.check
    "bar"
  end
end

class Bark
  def initialize(checker)
    @checker = checker
  end

  def call
    puts @checker.check
  end
end

and then just instantiate the Bark class with the module you need to get an object with the desired behavior:

Bark.new(Foo).call #=> "foo"
Bark.new(Bar).call #=> "bar"

CodePudding user response：

Odd problems require odd solutions. You could define Meouw::Foo and make it refer to Bar:

Meouw = Bark.dup
Meouw::Foo = Bar

This way, Foo within Meouw will resolve to Meouw::Foo (which is actually ::Bar) instead of the global ::Foo:

Meouw.new.call
# prints "bar"

CodePudding user response：

Why can't you keep it simple and inherit from Bark and override the call method?

class Meow < Bark
  def call
    puts Bar.check
  end
end

Meouw.new.call

# prints "bar"

If you want something more meta, you can use Class.new as well