instance_methods_upto_ancestor.rb

class Module
  method = instance_method(:instance_methods)
  define_method :instance_methods do |condition = true|
    return method.bind(self).call(condition) unless Module === condition
    anc = ancestors
    index = anc.index(condition) || -1
    anc[0..index].inject([]) { |methods, ancestor|
      methods.concat(ancestor.instance_methods(false))
    }.uniq
  end
end