String compression method in ruby

string_compression_ruby.rb

# https://github.com/alexavlonitis
# Simple string compression 'aaabbb' to 'a3b3'

def compress_string(text)
  consecutive_chars = text.each_char.chunk_while(&:==).map(&:join)

  consecutive_chars.map do |chars|
    chars_group = chars.split('')
    chars_group.first + chars_group.length.to_s
  end.join
end

## Convoluted manual way

def compress_string(text)
  result_array = []
  split_text = text.split('')

  counter = 1
  split_text.each.with_index(1) do |char, lookahead_index|
    result_array << char if counter == 1

    counter += 1 if result_array.last == split_text[lookahead_index]
    if result_array.last != split_text[lookahead_index] && counter != 1
      result_array << counter
      counter = 1
    end
  end

  result_array.join
end

## decompress string

def decompress_string(text)
  # subarray after every digit
  grouped_array_text = text.each_char.chunk_while { |i, j| j =~ /\A[0-9]\z/ }.to_a

  # if the subarray has a number (size > 1) then get the first value (letter)
  # and multiply the combined digits of the remainder
  grouped_array_text.map { |x| x.size > 1 ? x.shift * x.join.to_i : x.first }.join
end