The dangers of `alias` in ruby

alias.rb

class Parent
  def foo
    "Parent#foo"
  end
  alias :bar :foo
end

class Child < Parent
  def foo
    "Child#foo"
  end
end

Parent.new.foo # => "Parent#foo"
Parent.new.bar # => "Parent#foo"

Child.new.foo # => "Child#foo"
Child.new.bar # => "Parent#foo"