Before all methods hook example for stapler on #ruby IRC

before_all.rb

class BeforeAll < Module
  def initialize(before_method)
    @before_method = before_method
  end

  def prepended(base)
    base.instance_methods(false).each do |method_name|
      this_method = base.instance_method(method_name)
      before_method = @before_method
      define_method(method_name) do |*args, **kwargs, &block|
        method(before_method).call
        this_method.bind_call(self, *args, **kwargs, &block)
      end
    end
  end
end

class Foo
  def foo
    puts 'Foo'
  end

  private

  def bar
    puts 'Before ...'
  end

  prepend BeforeAll.new(:bar)
end

Foo.new.foo