Randomizing Cucumber outlines

feature_1.feature

Feature: Feature 1

  Scenario: A normal test
    * foo

  @Random(50)
  Scenario Outline:
    * foo
  Examples:
    | values |
    | 1      |
    | 2      |
    | 3      |
    | 4      |
    | 5      |
    | 6      |
    | 7      |
    | 8      |
    | 9      |
    | 0      |

feature_2.feature

Feature: Feature 2

  Scenario Outline:
    * foo
  @Random(20)
  Examples:
    | values |
    | 1      |
    | 2      |
    | 3      |
    | 4      |
    | 5      |
    | 6      |
    | 7      |
    | 8      |
    | 9      |
    | 0      |
  @Random(100)
  Examples:
    | values |
    | a      |
    | b      |

pick_random_tests.rb

require 'cucumber_analytics'


def choose_randomly(tag, rows)
  percent = tag[/\d+/].to_i
  percent /= 100.0

  sample_size = (rows.count * percent).to_i

  rows.sample(sample_size)
end


your_test_directory = Dir.pwd

world = CucumberAnalytics::World
directory = CucumberAnalytics::Directory.new(your_test_directory)


# Written for clarity, not efficiency. Could certainly use fewer collection iterations
all_tests = world.tests_in(directory)
all_outlines = all_tests.select { |test| test.is_a?(CucumberAnalytics::Outline) }
all_example_tables = all_outlines.collect { |outline| outline.examples }.flatten
randomized_example_tables = all_example_tables.select { |example| example.all_tags.any? { |tag| tag =~ /Random\(\d+\)/ } }


# Now that we've got all of the example rows, we need to randomly choose some of them to run
random_outline_rows = Array.new.tap { |rows|
  randomized_example_tables.each do |example|
    randomizer_tag = example.all_tags.select { |tag| tag =~ /Random\(\d+\)/ }.first # Assuming just one applicable randomizing tag
    example_rows = example.row_elements

    example_rows.shift # Need to get rid of the header row

    rows << choose_randomly(randomizer_tag, example_rows)
  end
}.flatten

# And then translate them into the familiar FILE:LINE form
final_runnable_tests = random_outline_rows.collect { |row| "#{row.get_ancestor(:feature_file).path}:#{row.source_line}" }


# Use them however you want at this point! Perhaps write them to a file and run them all?

File.open('my_random_tests.txt', 'w') { |file|
  file.puts final_runnable_tests
}

system('cucumber @my_random_tests.txt')