Distribute tests between pipelines

distribute.rb

number_of_pipelines = ENV['NUMBER_OF_PIPELINES'].to_i || 2

groups = [
  'spec/acceptance/**/*.feature',
  'spec/mailers/**/*_spec.rb',
  'spec/decorators/**/*_spec.rb',
  'spec/features/**/*_spec.rb',
  'spec/models/**/*_spec.rb',
  'spec/policies/**/*_spec.rb',
  'spec/adapters/**/*_spec.rb',
  'spec/graphql/**/*_spec.rb',
  'spec/state_handlers/**/*_spec.rb',
  'spec/requests/**/*_spec.rb',
  'spec/lib/**/*_spec.rb',
  'spec/db/**/*_spec.rb',
  'spec/workers/**/*_spec.rb',
  'spec/routing/**/*_spec.rb',
  'spec/controllers/**/*_spec.rb',
  'spec/helpers/**/*_spec.rb',
  'spec/services/**/*_spec.rb'
]

Dir.glob("{#{groups.join(',')}}").uniq.shuffle.each.with_index do |path, index|
  test_content = File.read(path)
  pipeline = index % number_of_pipelines

  if File.extname(path) == '.feature'
    (test_content[0] == '#') ?
      test_content = "# @pipeline#{pipeline}\n#{test_content}" :
      test_content = "@pipeline#{pipeline}\n#{test_content}"
  else
    test_lines = test_content.lines
    test_content = test_lines[0].gsub("do\n", ", pipeline#{pipeline}: true do\n") + test_lines[1..-1].join
  end

  File.open(path, 'w') { |f| f.write(test_content) }
end