Output the RSpec command to reproduce a test run

README.md

Output the RSpec command to reproduce a test run

How to use

• Add rspec_reproducible_order_command.rb to lib/.
• Use the formatter when running RSpec, in addition to usual formatters:

  rspec --format progress --format RspecReproducibleOrderCommand --out log/rspec_command.txt

• Shortened example output:

  rspec --order random:27344 ./spec/models/user_spec.rb:4 ...

On CircleCI

In .circleci/config.yml:

      - run:
          name: RSpec
          command: |
            mkdir -p $CIRCLE_TEST_REPORTS/rspec
            bundle exec rspec \
              --format RspecJunitFormatter --out $CIRCLE_TEST_REPORTS/rspec/rspec.xml \
              --format RspecReproducibleOrderCommand --out log/rspec_command.txt \
              --format progress \
              $(circleci tests glob 'spec/**/*_spec.rb' | circleci tests split --split-by=timings | xargs)
      - run:
          name: Command for reproducible test run
          when: on_fail
          command: |
            cat log/rspec_command.txt
            #
            # Use the following command to reproduce this exact RSpec run,
            # with the same examples in the same order
            # (you can triple-click to select the whole line):

rspec_reproducible_order_command.rb

RSpec::Support.require_rspec_core "formatters/base_formatter"

class RspecReproducibleOrderCommand < RSpec::Core::Formatters::BaseFormatter
  RSpec::Core::Formatters.register self, :seed, :dump_summary

  def seed(notification)
    self.seed_value = notification.seed if notification.seed_used?
  end

  def dump_summary(notification)
    output.puts [
      "rspec",
      order_option,
      notification.examples.map(&:location)
    ].flatten.join(" ")
  end

  private

    attr_accessor :seed_value

    def order_option
      if seed_value
        "--order random:#{seed_value}"
      else
        "--order defined"
      end
    end
end