# parallel_tests [![Gem Version](https://badge.fury.io/rb/parallel_tests.svg)](https://rubygems.org/gems/parallel_tests) [![Build Status](https://travis-ci.org/grosser/parallel_tests.svg)](https://travis-ci.org/grosser/parallel_tests/builds) [![Build status](https://github.com/grosser/parallel_tests/workflows/windows/badge.svg)](https://github.com/grosser/parallel_tests/actions?query=workflow%3Awindows) Speedup Test::Unit + RSpec + Cucumber + Spinach by running parallel on multiple CPU cores.
ParallelTests splits tests into even groups (by number of lines or runtime) and runs each group in a single process with its own database. Setup for Rails =============== [RailsCasts episode #413 Fast Tests](http://railscasts.com/episodes/413-fast-tests) ### Install `Gemfile`: ```ruby gem 'parallel_tests', group: [:development, :test] ``` ### Add to `config/database.yml` ParallelTests uses 1 database per test-process.
Process number123
ENV['TEST_ENV_NUMBER']'''2''3'
```yaml test: database: yourproject_test<%= ENV['TEST_ENV_NUMBER'] %> ``` ### Create additional database(s) rake parallel:create ### Copy development schema (repeat after migrations) rake parallel:prepare ### Run migrations in additional database(s) (repeat after migrations) rake parallel:migrate ### Setup environment from scratch (create db and loads schema, useful for CI) rake parallel:setup ### Drop all test databases rake parallel:drop ### Run! rake parallel:test # Test::Unit rake parallel:spec # RSpec rake parallel:features # Cucumber rake parallel:features-spinach # Spinach rake parallel:test[1] --> force 1 CPU --> 86 seconds rake parallel:test --> got 2 CPUs? --> 47 seconds rake parallel:test --> got 4 CPUs? --> 26 seconds ... Test by pattern with Regex (e.g. use one integration server per subfolder / see if you broke any 'user'-related tests) rake parallel:test[^test/unit] # every test file in test/unit folder rake parallel:test[user] # run users_controller + user_helper + user tests rake parallel:test['user|product'] # run user and product related tests rake parallel:spec['spec\/(?!features)'] # run RSpec tests except the tests in spec/features ### Example output 2 processes for 210 specs, ~ 105 specs per process ... test output ... 843 examples, 0 failures, 1 pending Took 29.925333 seconds ### Run an arbitrary task in parallel ```Bash RAILS_ENV=test parallel_test -e "rake my:custom:task" # or rake parallel:rake[my:custom:task] # limited parallelism rake parallel:rake[my:custom:task,2] ``` Running things once =================== ```Ruby require "parallel_tests" # preparation: # affected by race-condition: first process may boot slower than the second # either sleep a bit or use a lock for example File.lock ParallelTests.first_process? ? do_something : sleep(1) # cleanup: # last_process? does NOT mean last finished process, just last started ParallelTests.last_process? ? do_something : sleep(1) at_exit do if ParallelTests.first_process? ParallelTests.wait_for_other_processes_to_finish undo_something end end ``` Even test group run-times ========================= Test groups are often not balanced and will run for different times, making everything wait for the slowest group. Use these loggers to record test runtime and then use the recorded runtime to balance test groups more evenly. ### RSpec Rspec: Add to your `.rspec_parallel` (or `.rspec`) : --format progress --format ParallelTests::RSpec::RuntimeLogger --out tmp/parallel_runtime_rspec.log To use a custom logfile location (default: `tmp/parallel_runtime_rspec.log`), use the CLI: `parallel_test spec -t rspec --runtime-log my.log` ### Minitest Add to your `test_helper.rb`: ```ruby require 'parallel_tests/test/runtime_logger' if ENV['RECORD_RUNTIME'] ``` results will be logged to tmp/parallel_runtime_test.log when `RECORD_RUNTIME` is set, so it is not always required or overwritten. Loggers ======= RSpec: SummaryLogger -------------------- Log the test output without the different processes overwriting each other. Add the following to your `.rspec_parallel` (or `.rspec`) : --format progress --format ParallelTests::RSpec::SummaryLogger --out tmp/spec_summary.log RSpec: FailuresLogger ----------------------- Produce pastable command-line snippets for each failed example. For example: ```bash rspec /path/to/my_spec.rb:123 # should do something ``` Add to `.rspec_parallel` or use as CLI flag: --format progress --format ParallelTests::RSpec::FailuresLogger --out tmp/failing_specs.log (Not needed to retry failures, for that pass [--only-failures](https://relishapp.com/rspec/rspec-core/docs/command-line/only-failures) to rspec) Cucumber: FailuresLogger ----------------------- Log failed cucumber scenarios to the specified file. The filename can be passed to cucumber, prefixed with '@' to rerun failures. Usage: cucumber --format ParallelTests::Cucumber::FailuresLogger --out tmp/cucumber_failures.log Or add the formatter to the `parallel:` profile of your `cucumber.yml`: parallel: --format progress --format ParallelTests::Cucumber::FailuresLogger --out tmp/cucumber_failures.log Note if your `cucumber.yml` default profile uses `<%= std_opts %>` you may need to insert this as follows `parallel: <%= std_opts %> --format progress...` To rerun failures: cucumber @tmp/cucumber_failures.log Setup for non-rails =================== gem install parallel_tests # go to your project dir parallel_test parallel_rspec parallel_cucumber parallel_spinach - use `ENV['TEST_ENV_NUMBER']` inside your tests to select separate db/memcache/etc. (docker compose: expose it) - Only run a subset of files / folders: `parallel_test test/bar test/baz/foo_text.rb` - Pass test-options and files via `--`: `parallel_rspec -- -t acceptance -f progress -- spec/foo_spec.rb spec/acceptance` - Pass in test options, by using the -o flag (wrap everything in quotes): `parallel_cucumber -n 2 -o '-p foo_profile --tags @only_this_tag or @only_that_tag --format summary'` Options are: -n [PROCESSES] How many processes to use, default: available CPUs -p, --pattern [PATTERN] run tests matching this regex pattern --exclude-pattern [PATTERN] exclude tests matching this regex pattern --group-by [TYPE] group tests by: found - order of finding files steps - number of cucumber/spinach steps scenarios - individual cucumber scenarios filesize - by size of the file runtime - info from runtime log default - runtime when runtime log is filled otherwise filesize -m, --multiply-processes [FLOAT] use given number as a multiplier of processes to run -s, --single [PATTERN] Run all matching files in the same process -i, --isolate Do not run any other tests in the group used by --single(-s) --isolate-n [PROCESSES] Use 'isolate' singles with number of processes, default: 1. --highest-exit-status Exit with the highest exit status provided by test run(s) --specify-groups [SPECS] Use 'specify-groups' if you want to specify multiple specs running in multiple processes in a specific formation. Commas indicate specs in the same process, pipes indicate specs in a new process. Cannot use with --single, --isolate, or --isolate-n. Ex. $ parallel_tests -n 3 . --specify-groups '1_spec.rb,2_spec.rb|3_spec.rb' Process 1 will contain 1_spec.rb and 2_spec.rb Process 2 will contain 3_spec.rb Process 3 will contain all other specs --only-group INT[,INT] -e, --exec [COMMAND] execute this code parallel and with ENV['TEST_ENV_NUMBER'] -o, --test-options '[OPTIONS]' execute test commands with those options -t, --type [TYPE] test(default) / rspec / cucumber / spinach --suffix [PATTERN] override built in test file pattern (should match suffix): '_spec.rb$' - matches rspec files '_(test|spec).rb$' - matches test or spec files --serialize-stdout Serialize stdout output, nothing will be written until everything is done --prefix-output-with-test-env-number Prefixes test env number to the output when not using --serialize-stdout --combine-stderr Combine stderr into stdout, useful in conjunction with --serialize-stdout --non-parallel execute same commands but do not in parallel, needs --exec --no-symlinks Do not traverse symbolic links to find test files --ignore-tags [PATTERN] When counting steps ignore scenarios with tags that match this pattern --nice execute test commands with low priority. --runtime-log [PATH] Location of previously recorded test runtimes --allowed-missing [INT] Allowed percentage of missing runtimes (default = 50) --unknown-runtime [FLOAT] Use given number as unknown runtime (otherwise use average time) --first-is-1 Use "1" as TEST_ENV_NUMBER to not reuse the default test environment --fail-fast Stop all groups when one group fails (best used with --test-options '--fail-fast' if supported --verbose Print debug output --verbose-process-command Displays only the command that will be executed by each process --verbose-rerun-command When there are failures, displays the command executed by each process that failed --quiet Print only tests output -v, --version Show Version -h, --help Show this. You can run any kind of code in parallel with -e / --exec parallel_test -n 5 -e 'ruby -e "puts %[hello from process #{ENV[:TEST_ENV_NUMBER.to_s].inspect}]"' hello from process "2" hello from process "" hello from process "3" hello from process "5" hello from process "4"
1 Process2 Processes4 Processes
RSpec spec-suite18s14s10s
Rails-ActionPack88s53s44s
TIPS ==== ### RSpec - Add a `.rspec_parallel` to use different options, e.g. **no --drb** - Remove `--loadby` from `.rspec` - Instantly see failures (instead of just a red F) with [rspec-instafail](https://github.com/grosser/rspec-instafail) - Use [rspec-retry](https://github.com/NoRedInk/rspec-retry) (not rspec-rerun) to rerun failed tests. - [JUnit formatter configuration](https://github.com/grosser/parallel_tests/wiki#with-rspec_junit_formatter----by-jgarber) - Use [parallel_split_test](https://github.com/grosser/parallel_split_test) to run multiple scenarios in a single spec file, concurrently. (`parallel_tests` [works at the file-level and intends to stay that way](https://github.com/grosser/parallel_tests/issues/747#issuecomment-580216980)) ### Cucumber - Add a `parallel: foo` profile to your `config/cucumber.yml` and it will be used to run parallel tests - [ReportBuilder](https://github.com/rajatthareja/ReportBuilder) can help with combining parallel test results - Supports Cucumber 2.0+ and is actively maintained - Combines many JSON files into a single file - Builds a HTML report from JSON with support for debug msgs & embedded Base64 images. ### General - [ZSH] use quotes to use rake arguments `rake "parallel:prepare[3]"` - [Memcached] use different namespaces
e.g. `config.cache_store = ..., namespace: "test_#{ENV['TEST_ENV_NUMBER']}"` - Debug errors that only happen with multiple files using `--verbose` and [cleanser](https://github.com/grosser/cleanser) - `export PARALLEL_TEST_PROCESSORS=13` to override default processor count - Shell alias: `alias prspec='parallel_rspec -m 2 --'` - [Spring] Add the [spring-commands-parallel-tests](https://github.com/DocSpring/spring-commands-parallel-tests) gem to your `Gemfile` to get `parallel_tests` working with Spring. - `--first-is-1` will make the first environment be `1`, so you can test while running your full suite.
`export PARALLEL_TEST_FIRST_IS_1=true` will provide the same result - [email_spec and/or action_mailer_cache_delivery](https://github.com/grosser/parallel_tests/wiki) - [zeus-parallel_tests](https://github.com/sevos/zeus-parallel_tests) - [Distributed Parallel Tests on CI systems)](https://github.com/grosser/parallel_tests/wiki/Distributed-Parallel-Tests-on-CI-systems) learn how `parallel_tests` can run on distributed servers such as Travis and GitLab-CI. Also shows you how to use parallel_tests without adding `TEST_ENV_NUMBER`-backends - [Capybara setup](https://github.com/grosser/parallel_tests/wiki) - [Sphinx setup](https://github.com/grosser/parallel_tests/wiki) - [Capistrano setup](https://github.com/grosser/parallel_tests/wiki/Remotely-with-capistrano) let your tests run on a big box instead of your laptop Contribute your own gotchas to the [Wiki](https://github.com/grosser/parallel_tests/wiki) or even better open a PR :) Authors ==== inspired by [pivotal labs](https://blog.pivotal.io/labs/labs/parallelize-your-rspec-suite) ### [Contributors](https://github.com/grosser/parallel_tests/contributors) - [Charles Finkel](http://charlesfinkel.com/) - [Indrek Juhkam](http://urgas.eu) - [Jason Morrison](http://jayunit.net) - [jinzhu](http://github.com/jinzhu) - [Joakim Kolsjö](http://www.rubyblocks.se) - [Kevin Scaldeferri](http://kevin.scaldeferri.com/blog/) - [Kpumuk](http://kpumuk.info/) - [Maksim Horbul](http://github.com/mhorbul) - [Pivotal Labs](http://www.pivotallabs.com) - [Rohan Deshpande](http://github.com/rdeshpande) - [Tchandy](http://thiagopradi.net/) - [Terence Lee](http://hone.heroku.com/) - [Will Bryant](http://willbryant.net/) - [Fred Wu](http://fredwu.me) - [xxx](https://github.com/xxx) - [Levent Ali](http://purebreeze.com/) - [Michael Kintzer](https://github.com/rockrep) - [nathansobo](https://github.com/nathansobo) - [Joe Yates](http://titusd.co.uk) - [asmega](http://www.ph-lee.com) - [Doug Barth](https://github.com/dougbarth) - [Geoffrey Hichborn](https://github.com/phene) - [Trae Robrock](https://github.com/trobrock) - [Lawrence Wang](https://github.com/levity) - [Sean Walbran](https://github.com/seanwalbran) - [Lawrence Wang](https://github.com/levity) - [Potapov Sergey](https://github.com/greyblake) - [Łukasz Tackowiak](https://github.com/lukasztackowiak) - [Pedro Carriço](https://github.com/pedrocarrico) - [Pablo Manrubia Díez](https://github.com/pmanrubia) - [Slawomir Smiechura](https://github.com/ssmiech) - [Georg Friedrich](https://github.com/georg) - [R. 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