class RuboCop::Cop::Style::MethodMissing

end
super
# …
def method_missing(name, *args)
end
# …
def respond_to_missing?(name, include_private)
#good
end
# …
def method_missing(name, *args)
#bad
@example
defining ‘respond_to_missing?` and falling back on `super`.
This cop checks for the presence of `method_missing` without also

def calls_super?(node) 

def calls_super?(node)
  node.descendants.any?(&:zsuper_type?)
end

def check(node) 

def check(node)
  return if calls_super?(node) && implements_respond_to_missing?(node)
  add_offense(node)
end

def implements_respond_to_missing?(node) 

def implements_respond_to_missing?(node)
  node.parent.each_child_node(node.type).any? do |sibling|
    sibling.method?(:respond_to_missing?)
  end
end

def message(node) 

def message(node)
  instructions = []
  unless implements_respond_to_missing?(node)
    instructions << 'define `respond_to_missing?`'.freeze
  end
  unless calls_super?(node)
    instructions << 'fall back on `super`'.freeze
  end
  format(MSG, instructions: instructions.join(' and '))
end

def on_def(node) 

def on_def(node)
  return unless node.method?(:method_missing)
  check(node)
end