This gem lets you run your RSpec examples in parallel across your CPUs. Each worker gets its own database to avoid conflicts.

Add this to your application's Gemfile:

group :development, :test do gem 'parallel_rspec' end

Or if you use Spring:

group :development, :test do gem 'spring-prspec' end

And then execute:

$ bundle 

This version of ParallelRSpec has been tested with RSpec 3.12.

By default, ParallelRSpec will use four workers. If you would like to use more, set an environment variable:

$ export WORKERS=8 

ParallelRSpec runs each worker with its own copy of the test database to avoid locking and deadlocking problems. To create these and populate them with your schema, run:

$ bundle exec rake db:parallel:create db:parallel:prepare 

ParallelRSpec will automatically make the database name for each worker based on the name you used for the test environment in config/database.yml. For example, if your normal test database is foo_test, worker 1 will keep using foo_test but worker 2's database will be foo_test2.

You're then ready to run specs in parallel:

$ bundle exec prspec spec/my_spec.rb spec/another_spec.rb 

Or if you use Spring:

$ bundle exec spring prspec spec/my_spec.rb spec/another_spec.rb 

You may like to make an alias:

$ alias prspec='bundle exec spring prspec' $ prspec spec/my_spec.rb spec/another_spec.rb 

When you change WORKERS, don't forget to restart Spring and re-run the create and populate steps above if necessary.

By default, there's a task called parallel_rspec which will run all specs. To make a custom rake task which uses parallel_rspec with different options, inherit from ParallelRSpec::RakeTask, for example:

 require 'parallel_rspec' ParallelRSpec::RakeTask.new(:prspec) do |t| ENV['WORKERS'] = '8' t.pattern = "spec/**/*_spec.rb" t.rspec_opts = "--tag parallel" # etc... end

If you'd like code to run after parallel_rspec has created each worker, you can specify a block to run:

 ParallelRSpec.configure do |config| config.after_fork do |worker_number| puts "I am worker #{worker_number}" end end

You might also want to detect whether your spec suite is running under ParallelRSpec or not:

 do_something unless ParallelRSpec.running?

ParallelRSpec can't parallelize the specs in groups that use before(:context) or after(:context) (AKA before(:all) or after(:all)) hooks, since these may mean that there is state shared between examples.

Bug reports and pull requests are welcome on GitHub at https://github.com/willbryant/parallel_rspec.

• Charles Horn (@hornc)
• Roger Nesbitt (@mogest)
• Erik Paasonen (@erikpaasonen)

The gem is available as open source under the terms of the MIT License.

Copyright (c) Powershop New Zealand Ltd, 2015. Copyright (c) Will Bryant, 2023.