RSpec::OrderedCommandFormatter

When running an RSpec suite in parallelized containers on a Continuous Integration platform, the suite's spec files are split in multiple groups, each one being run in one container.

In order to reproduce a given container's test run, one needs to know what examples ran, and what was the random seed.

This formatter aims at making the process easier by producing a copy-pastable rspec command that includes the random seed and the list of examples.

Installation

Add this line to your application's Gemfile:

gem 'rspec-ordered_command_formatter', group: :test

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec-ordered_command_formatter

Usage

Simply pass the formatter to the rspec command's options. For example:

$ rspec --format RSpec::OrderedCommandFormatter --out log/rspec_command.txt

Example 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 RSpec::OrderedCommandFormatter --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):
+       - store_artifacts:
+           path: log

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/cookpad/rspec-ordered_command_formatter.