Add to the application's Gemfile:
gem 'test_balancer', github: 'Philwi/test_balancer', branch: 'main'
The gem provides a CLI to balance the tests for multiple CI-Nodes. You can pass a folder with xmls generated from Minitest Reporter.
This will generate a file minitest_split.json in the root of the application. This file contains the distributed tests for the CI-Nodes.
./bin/test_balancer from_xmls ./test/sample_xmls --subsets 3
You can also use multiple test suite execution times to calculate the median or trimean of the execution times. This will generate a file minitest_split.json in the root of the application. This file contains the distributed tests for the CI-Nodes.
./bin/test_balancer from_xmls_with_multiple_test_executions ./test --subsets 3
If you have a directory with xmls generated from Minitest Reporter, you can use the following approach:
xml_files = Dir.glob('test/**/*_test.xml')
subsets = TestBalancer.calculate_distributed_tests_from_xml_files(xml_files: xml_files, subset_count: 2)
If you want to write a file to use the minitest booster configuration for your CI, you can use the following approach:
TestBalancer.write_subsets_to_minitest_booster_file(subsets:, destination_file_path: 'minitest_split.json')
Add to the minitest test_helper.rb file:
require 'minitest/reporters'
Minitest::Reporters.use! [TestBalancer::ExecutionTimeReporter.new] if ENV["WRITE_EXECUTION_TIME_FILE"]
Run your tests with the environment variable WRITE_EXECUTION_TIME_FILE set to true:
WRITE_EXECUTION_TIME_FILE=true bundle exec rake test
This will create a file execution_times.json in the root of the application. This file contains the execution times of the tests in the last test run.
To balance the tests for multiple CI-Nodes use the TestBalancer::TestBalancer class:
file = File.read('execution_times.json')
tests_with_execution_time = JSON.parse(file)
test_balancer = TestBalancer::TestBalancer.new
test_balancer.call(tests_with_execution_time: tests_with_execution_time, subset_count: 2)
Now you get a list of distributed test files for the two CI-Nodes:
[
{ :subset_1=>{:time=>9.509755814999153, :tests=>["test/sample_tests/sample_test_one_test.rb"] },
{ :subset_2=>{:time=>8.32, :tests=>["test/sample_tests/sample_test_two_test.rb", "test/sample_tests/sample_test_three_test.rb"] }
]
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 the created tag, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/test_balancer. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.
The gem is available as open source under the terms of the MIT License.
Everyone interacting in the TestBalancer project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.