Some ways to pass mutant tests

case_when.rb

# alternative solutions to https://blog.arkency.com/semantic-blind-spot-in-ruby-case-statement/
class CaseWhen
  def call(number)
    boundaries = [0, 4, 8, 11]
    messages   = ['low value', 'medium value', 'high value']
    boundaries.each_cons(2).zip messages do |(low, high), desc|
      return desc if low <= number && number < high
    end
    'invalid value'
  end
end


class CaseWhen
  def call(number)
    case number
    when  11.., ...0
      'invalid value'
    when ..3
      'low value'
    when ..7
      'medium value'
    else
      'high value'
    end
  end


class CaseWhen
  def call(number)
    return 'low value'    if 0.equal? number/4
    return 'medium value' if 0.equal? number/8
    return 'high value'   if 0.equal? number/11
    'invalid value'
  end
end