class RuboCop::Cop::Style::NestedParenthesizedCalls

method1(method2 arg, method3, arg)
# bad
method1(method2(arg), method3(arg))
# good
@example
of a parenthesized method call.
This cop checks for unparenthesized method calls in the argument list

def allowed_omission?(send_node) 

def allowed_omission?(send_node)
  !send_node.arguments? || send_node.parenthesized? ||
    send_node.setter_method? || send_node.operator_method? ||
    whitelisted?(send_node)
end

def autocorrect(nested) 

def autocorrect(nested)
  first_arg = nested.first_argument.source_range
  last_arg = nested.last_argument.source_range
  leading_space =
    range_with_surrounding_space(range: first_arg,
                                 side: :left).begin.resize(1)
  lambda do |corrector|
    corrector.replace(leading_space, '(')
    corrector.insert_after(last_arg, ')')
  end
end

def on_send(node) 

def on_send(node)
  return unless node.parenthesized?
  node.each_child_node(:send, :csend) do |nested|
    next if allowed_omission?(nested)
    add_offense(nested,
                location: nested.source_range,
                message: format(MSG, source: nested.source))
  end
end

def whitelisted?(send_node) 

def whitelisted?(send_node)
  send_node.parent.arguments.one? &&
    whitelisted_methods.include?(send_node.method_name.to_s) &&
    send_node.arguments.one?
end

def whitelisted_methods 

def whitelisted_methods
  cop_config['Whitelist'] || []
end