Parallel Tests

Using the parallel_test gem

Running parallel Cucumber and Capybara based tests on top of Sauce is very easy. This document covers using the parallel_tests gem for running multiple Cucumber features at once.

The parallel_tests gem provides two executables, parallel_rspec and parallel_cucumber, which use the gem's parallelization magic to invoke rspec or cucumber respectively.

If for example, you had a dual core computer, and a features/ directory with 10 .feature files in it, you could run:

% bundle exec parallel_cucumber features

And the command would run a two Cucumber processes at the same time, each executing one of the 10 feature files.

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Parallel Testing Tips

In order to run parallel tests effectively, your test code must be able to run at the same time as other tests.

• Avoid forcing your tests to start up a server process, not only does this slow things down, but it also increases the likelihood that your tests will try to start a server at the same time and conflict. Instead use a remote staging environment, ideally one that closely represents production and can handle many clients simultaneously
• Avoid shared or hard-coded data in your tests, if you need an email address or some other form of fake data, generate it yourself (check out the Faker gem).