Contents

# frozen_string_literal: true

module RuboCop
  module Cop
    module Lint
      # In math and Python, we can use `x < y < z` style comparison to compare
      # multiple value. However, we can't use the comparison in Ruby. However,
      # the comparison is not syntax error. This cop checks the bad usage of
      # comparison operators.
      #
      # @example
      #
      #   # bad
      #
      #   x < y < z
      #   10 <= x <= 20
      #
      # @example
      #
      #   # good
      #
      #   x < y && y < z
      #   10 <= x && x <= 20
      class MultipleComparison < Base
        extend AutoCorrector

        MSG = 'Use the `&&` operator to compare multiple values.'

        def_node_matcher :multiple_compare?, <<~PATTERN
          (send (send _ {:< :> :<= :>=} $_) {:< :> :<= :>=} _)
        PATTERN

        def on_send(node)
          return unless (center = multiple_compare?(node))

          add_offense(node) do |corrector|
            new_center = "#{center.source} && #{center.source}"

            corrector.replace(center, new_center)
          end
        end
      end
    end
  end
end

Version data entries

4 entries across 4 versions & 2 rubygems

Version	Path
grape-extra_validators-2.0.0	vendor/bundle/ruby/2.6.0/gems/rubocop-0.90.0/lib/rubocop/cop/lint/multiple_comparison.rb
rubocop-0.90.0	lib/rubocop/cop/lint/multiple_comparison.rb
rubocop-0.89.1	lib/rubocop/cop/lint/multiple_comparison.rb
rubocop-0.89.0	lib/rubocop/cop/lint/multiple_comparison.rb