How to run tests in parallel locally?

[tibbon]

I have a machine with 8+ threads. How can I run my tests in parallel with these reports on my local system?

[ArturT]

Here is example: https://github.com/ArturT/knapsack#how-to-run-tests-for-particular-ci-node-in-your-development-environment

Could you share more info about your project context. What CI provider do you use? How long is your test suite? RSpec or something else? Why do you want to run test suite in development across threads? Is it small test suite so it's faster in development than pushing to CI?

If you want to run threads using parallel_tests gem then you can take a look on knapsack_pro examples https://github.com/KnapsackPro/knapsack_pro-ruby#how-to-run-knapsack_pro-with-parallel_tests-gem

[tibbon]

Thanks for such a fast follow up!

My test suite is a mixture of Minitest (migrating away from) and RSpec. Between the two of them the suite is around 4-5 minutes to run fully, but if I could get that down to under a minute it would be great.

We use CircleCI, which is great. It's only building on pull requests right now, and I probably could just push to a work in progress branch more. Between building a VM and everything it's 5-8 minutes on Circle to complete.

I'll check out those examples

[ArturT]

Regarding idea how to lower down the time of builds on CircleCI you could do this:

1. Use CircleCI 2.0 which is faster. If you need something specific for your project then you can use custom Docker image. Other than that you can use default Docker images provided by CircleCI. I wrote article with an example how to configure CircleCI 2.0 with ruby + capybara
   http://docs.knapsackpro.com/2017/circleci-2-0-capybara-feature-specs-selenium-webdriver-with-chrome-headless

2. You have at the moment 2 different test runners minitest and RSpec and below setup is something I recommended for a few companies. You can always get optimal test suite split (the fastest time execution of your tests) by doing:

Step 1: run your minitest test suite with bundle exec rake knapsack_pro:minitest
Step 2: run your RSpec test suite with dynamic RSpec allocation across CI nodes (it's called knapsack_pro Queue Mode) bundle exec rake knapsack_pro:queue:rspec. Thanks to that the dynamic RSpec tests allocation will fill timing gaps across CI nodes so your whole build will have optimal time no matter if your tests have random time execution due to some long-running features specs or external requests in tests. No matter the CI nodes random performance.

You can take a look how dynamic RSpec allocation works with knapsack_pro Queue Mode, here is video at https://knapsackpro.com/

And here is explanation how to configure the proper order of knapsack_pro commands: https://github.com/KnapsackPro/knapsack_pro-ruby#what-is-optimal-order-of-test-commands

If you just want to take a look at knapsack_pro configuration options please see:
http://docs.knapsackpro.com/knapsack_pro-ruby/guide/

Let me know if I could help more :)

[adis-io]

I don't know, may be somebody already asked about it.
Here is the question, my whole test suit takes huge amount of time. But with parallel_tests (6 cores) it takes about - 30 min. Can I use parallel_tests to generate report?

[ArturT]

@adis-io Here is an example how to run knapsack_pro with parallel_tests gem https://github.com/KnapsackPro/knapsack_pro-ruby#how-to-run-knapsack_pro-with-parallel_tests-gem

[ArturT]

I added one more example of how to use paralell_tests with knapsack_pro Queue Mode to utilize machine resource on a single CI machine.

https://github.com/KnapsackPro/knapsack_pro-ruby#parallel_tests-with-knapsack_pro-on-single-ci-machine

There are bash scripts that can be reused.