# frozen_string_literal: true module RuboCop module Cop module Style # This cop 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. # # @example EnforcedStyle: always # # bad # foo.save and return # # # bad # if foo and bar # end # # # good # foo.save && return # # # good # if foo && bar # end # # @example EnforcedStyle: conditionals (default) # # bad # if foo and bar # end # # # good # foo.save && return # # # good # foo.save and return # # # good # if foo && bar # end class AndOr < Base include ConfigurableEnforcedStyle include RangeHelp extend AutoCorrector MSG = 'Use `%s` instead of `%s`.' def on_and(node) process_logical_operator(node) if style == :always end alias on_or on_and def on_if(node) on_conditionals(node) if style == :conditionals end alias on_while on_if alias on_while_post on_if alias on_until on_if alias on_until_post on_if private 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? correct_other(expr, corrector) elsif expr.assignment? correct_other(expr, corrector) end end corrector.replace(node.loc.operator, node.alternate_operator) end end def on_conditionals(node) node.condition.each_node(*AST::Node::OPERATOR_KEYWORDS) do |operator| process_logical_operator(operator) end end def message(node) format(MSG, prefer: node.alternate_operator, current: node.operator) end 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) corrector.replace(whitespace_before_arg(node), '(') corrector.insert_after(node.last_argument, ')') end def correct_setter(node, corrector) corrector.insert_before(node.receiver, '(') corrector.insert_after(node.last_argument, ')') end # ! is a special case: # 'x and !obj.method arg' can be auto-corrected if we # recurse down a level and add parens to 'obj.method arg' # however, 'not x' also parses as (send x :!) 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 def correct_other(node, corrector) return if node.source_range.begin.is?('(') corrector.wrap(node, '(', ')') end def correctable_send?(node) !node.parenthesized? && node.arguments? && !node.method?(:[]) end 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 end end end end