class RuboCop::Cop::Lint::FlipFlop

Looks for uses of flip-flop operator based on the Ruby Style Guide.

Here is the history of flip-flops in Ruby. flip-flop operator is deprecated in Ruby 2.6.0 and the deprecation has been reverted by Ruby 2.7.0 and backported to Ruby 2.6. See: bugs.ruby-lang.org/issues/5400

@example

# bad
(1..20).each do |x|
  puts x if (x == 5) .. (x == 10)
end

# good
(1..20).each do |x|
  puts x if (x >= 5) && (x <= 10)
end