def increment_string(string)
  updated_string = ""

...

def increment_string(string)
  updated_string = ""

...

def increment_string string
  string.next
end
...

def incrementString string
    string.split('').map {|letter| letter.succ}.join
end

def incrementString string
    string.succ
end

def incrementString string
	offset = -1
	loop do
...

def incrementString string
    string.tr('A-YZ­a-yz0-89',­ 'B-ZA­b-za1-90')
end

>> %w(Pending Processing Executed Canceled).each_index.to_a
=> [0, 1, 2, 3]

def find_or_create_by(attrs)
  where(attrs).first || create(attrs)
end

N/A - depends on used database

(0..%w(Pending Processing Executed Canceled).size-1).to_a

(0...%w(Pending Processing Executed Canceled).size).to_a