class Brakeman::CheckDivideByZero

def check_division result
  return unless original? result
  call = result[:call]
  denominator = call.first_arg
  if number? denominator and denominator.value == 0
    numerator = call.target
    if number? numerator
      if numerator.value.is_a? Float
        return # 0.0 / 0 is NaN and 1.0 / 0 is Infinity
      else
        confidence = :medium
      end
    else
      confidence = :weak
    end
    warn :result => result,
      :warning_type => "Divide by Zero",
      :warning_code => :divide_by_zero,
      :message => "Potential division by zero",
      :confidence => confidence,
      :user_input => denominator,
      :cwe_id => [369]
  end
end

def run_check
  tracker.find_call(:method => :"/").each do |result|
    check_division result
  end
end