class RuboCop::Cop::Style::SymbolProc

def autocorrect(node)
  @corrections << lambda do |corrector|
    block_method, _block_args, block_body = *node
    _receiver, method_name, _args = *block_body
    replacement = "#{block_method.loc.expression.source}" \
                  "(&:#{method_name})"
    corrector.replace(node.loc.expression, replacement)
  end
end

def ignored_method?(name)
  ignored_methods.include?(name.to_s)
end

def ignored_methods
  cop_config['IgnoredMethods']
end

def on_block(node)
  block_send, block_args, block_body = *node
  _breceiver, bmethod_name, bargs = *block_send
  # we should ignore lambdas
  return if bmethod_name == :lambda
  return if ignored_method?(bmethod_name)
  # File.open(file) { |f| f.readlines }
  return if bargs
  # something { |x, y| ... }
  return unless block_args.children.size == 1
  return unless block_body && block_body.type == :send
  receiver, method_name, args = *block_body
  # method in block must be invoked on a lvar without args
  return if args
  return if receiver.type != :lvar
  block_arg_name, = *block_args.children.first
  receiver_name, = *receiver
  return if block_arg_name != receiver_name
  add_offense(node,
              :expression,
              format(MSG,
                     method_name,
                     bmethod_name))
end