class RuboCop::Cop::Lint::RequireParentheses

This cop checks for expressions where there is a call to a predicate method with at least one argument, where no parentheses are used around the parameter list, and a boolean operator, && or ||, is used in the last argument.

The idea behind warning for these constructs is that the user might be under the impression that the return value from the method call is an operand of &&/||.

@example

if day.is? :tuesday && month == :jan
  ...
end

Constants

MSG

Public Instance Methods

on_send(node) click to toggle source
# File lib/rubocop/cop/lint/require_parentheses.rb, line 26
def on_send(node)
  _receiver, method_name, *args = *node

  return if parentheses?(node)
  return if args.empty?

  if ternary?(args.first)
    check_ternary(args.first, node)
  elsif predicate?(method_name)
    # We're only checking predicate methods. There would be false
    # positives otherwise.
    check_send(args.last, node)
  end
end

Private Instance Methods

check_send(arg, node) click to toggle source
# File lib/rubocop/cop/lint/require_parentheses.rb, line 54
def check_send(arg, node)
  add_offense(node, :expression) if offense?(arg)
end
check_ternary(arg, node) click to toggle source
# File lib/rubocop/cop/lint/require_parentheses.rb, line 43
def check_ternary(arg, node)
  condition, = *arg
  return unless offense?(condition)

  expr = node.source_range
  range = Parser::Source::Range.new(expr.source_buffer,
                                    expr.begin_pos,
                                    condition.source_range.end_pos)
  add_offense(range, range)
end
offense?(node) click to toggle source
# File lib/rubocop/cop/lint/require_parentheses.rb, line 62
def offense?(node)
  [:and, :or].include?(node.type)
end
predicate?(method_name) click to toggle source
# File lib/rubocop/cop/lint/require_parentheses.rb, line 58
def predicate?(method_name)
  method_name.to_s.end_with?('?')
end