class RuboCop::Cop::Style::AndOr

Checks for uses of `and` and `or`, and suggests using `&&` and `||` instead. It can be configured to check only in conditions or in all contexts.

@safety

Autocorrection is unsafe because there is a different operator precedence
between logical operators (`&&` and `||`) and semantic operators (`and` and `or`),
and that might change the behavior.

@example EnforcedStyle: conditionals (default)

# bad
if foo and bar
end

# good
foo.save && return

# good
foo.save and return

# good
if foo && bar
end

@example EnforcedStyle: always

# bad
foo.save and return

# bad
if foo and bar
end

# good
foo.save && return

# good
if foo && bar
end

Constants

MSG

Public Instance Methods

on_and(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 51
def on_and(node)
  process_logical_operator(node) if style == :always
end
Also aliased as: on_or
on_if(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 56
def on_if(node)
  on_conditionals(node) if style == :conditionals
end
on_or(node)
Alias for: on_and
on_until(node)
Alias for: on_if
on_until_post(node)
Alias for: on_if
on_while(node)
Alias for: on_if
on_while_post(node)
Alias for: on_if

Private Instance Methods

correct_not(node, receiver, corrector) click to toggle source

! is a special case: 'x and !obj.method arg' can be autocorrected if we recurse down a level and add parens to 'obj.method arg' however, 'not x' also parses as (send x :!)

# File lib/rubocop/cop/style/and_or.rb, line 117
def correct_not(node, receiver, corrector)
  if node.prefix_bang?
    return unless receiver.send_type?

    correct_send(receiver, corrector)
  elsif node.prefix_not?
    correct_other(node, corrector)
  else
    raise 'unrecognized unary negation operator'
  end
end
correct_other(node, corrector) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 129
def correct_other(node, corrector)
  return if node.source_range.begin.is?('(')

  corrector.wrap(node, '(', ')')
end
correct_send(node, corrector) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 95
def correct_send(node, corrector)
  return correct_not(node, node.receiver, corrector) if node.method?(:!)
  return correct_setter(node, corrector) if node.setter_method?
  return correct_other(node, corrector) if node.comparison_method?

  return unless correctable_send?(node)

  whitespace_before_arg_range = whitespace_before_arg(node)
  corrector.remove(whitespace_before_arg_range)
  corrector.insert_before(whitespace_before_arg_range, '(')
  corrector.insert_after(node.last_argument, ')')
end
correct_setter(node, corrector) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 108
def correct_setter(node, corrector)
  corrector.insert_before(node.receiver, '(')
  corrector.insert_after(node.last_argument, ')')
end
correctable_send?(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 143
def correctable_send?(node)
  !node.parenthesized? && node.arguments? && !node.method?(:[])
end
keep_operator_precedence(corrector, node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 135
def keep_operator_precedence(corrector, node)
  if node.or_type? && node.parent&.and_type?
    corrector.wrap(node, '(', ')')
  elsif node.and_type? && node.rhs.or_type?
    corrector.wrap(node.rhs, '(', ')')
  end
end
message(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 91
def message(node)
  format(MSG, prefer: node.alternate_operator, current: node.operator)
end
on_conditionals(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 85
def on_conditionals(node)
  node.condition.each_node(*AST::Node::OPERATOR_KEYWORDS) do |operator|
    process_logical_operator(operator)
  end
end
process_logical_operator(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 66
def process_logical_operator(node)
  return if node.logical_operator?

  message = message(node)
  add_offense(node.loc.operator, message: message) do |corrector|
    node.each_child_node do |expr|
      if expr.send_type?
        correct_send(expr, corrector)
      elsif expr.return_type? || expr.assignment?
        correct_other(expr, corrector)
      end
    end

    corrector.replace(node.loc.operator, node.alternate_operator)

    keep_operator_precedence(corrector, node)
  end
end
whitespace_before_arg(node) click to toggle source
# File lib/rubocop/cop/style/and_or.rb, line 147
def whitespace_before_arg(node)
  begin_paren = node.loc.selector.end_pos
  end_paren = begin_paren
  # Increment position of parenthesis, unless message is a predicate
  # method followed by a non-whitespace char (e.g. is_a?String).
  end_paren += 1 unless /\?\S/.match?(node.source)
  range_between(begin_paren, end_paren)
end