🚀 TurboTests

July 19, 2026 · View on GitHub

🚀 TurboTests

if ci_badges.map(&:color).detect { it != "green"} ☝️ let me know, as I may have missed the discord notification.

if ci_badges.map(&:color).all? { it == "green"} 👇️ send money so I can do more of this. FLOSS maintenance is now my full-time job.

👣 How will this project approach the September 2025 hostile takeover of RubyGems? 🚑️

I've summarized my thoughts in this blog post.

🌻 Synopsis

Hard Fork Note
I (@pboling) discussed merging this project back into the original `turbo_tests` with @ilyazub, and we might move in that direction, but it will take time. Since I need this now I'm releasing it as a separate gem/project. We'll be discussing potentially unifying the projects again soon.

turbo_tests2 is an RSpec parallel test runner built on grosser/parallel_tests. It uses parallel_tests for process counts, file grouping, and runtime balancing, then replaces interleaved worker output with incremental summarized RSpec reporting. Source code of this gem is based on Discourse and RubyGems work in this area.

Incremental summarized output doesn't fit the vision of the parallel_tests author, and RSpec doesn't support built-in parallel testing yet. This gem targets RSpec, not every framework supported by parallel_tests, and may not be useful once one of the issues above is implemented.

Why incremental output?

parallel_tests is great, but parallel RSpec output is hard to read:


$ bundle exec rake parallel_tests:spec[^spec/search]
.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Finished in 1 minute 6.92 seconds (files took 6.95 seconds to load)
2616 examples, 0 failures

.........................................................................................................................................F........................................................................................................................................F..............................................................................................................................................................................................................................................................................................

Finished in 1 minute 35.05 seconds (files took 6.26 seconds to load)
2158 examples, 2 failures

.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Finished in 1 minute 35.05 seconds (files took 6.26 seconds to load)
2158 examples, 0 failures

turbo_tests2 output looks like regular rspec:

$ bundle exec turbo_tests2
..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................F........................................................................................................................................F..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Finished in 2 minute 25.15 seconds (files took 0 seconds to load)
6873 examples, 2 failures

💡 Info you can shake a stick at

Tokens to Remember
Works with JRuby
Works with Truffle Ruby
Works with MRI Ruby 4
Works with MRI Ruby 3
Works with MRI Ruby 2
Support & Community
Source
Documentation
Compliance
Style
Maintainer 🎖️
`...` 💖	🧊 🐙 🛖 🧪

Compatibility

Compatible with MRI Ruby 2.4.0+, and concordant releases of JRuby, and TruffleRuby. CI workflows and Appraisals are generated for MRI Ruby 2.4+. This test floor is configured by ruby.test_minimum in .kettle-jem.yml and may be higher than the gem's runtime compatibility floor when legacy Rubies are not practical for the current toolchain.

The amazing test matrix is powered by the kettle-dev stack.

How kettle-dev manages complexity in tests

Gem	Source	Role
appraisal2	GitHub	multi-dependency Appraisal matrix generation
appraisal2-rubocop	GitHub	RuboCop Appraisal generator integration
kettle-dev	GitHub	development, release, and CI workflow tooling
kettle-jem	GitHub	Appraisals & CI workflow templates
kettle-soup-cover	GitHub	SimpleCov coverage policy and reporting
kettle-test	GitHub	standard test runner and coverage harness
rubocop-lts	GitHub	Ruby-version-aware linting

Federated DVCS

Find this repo on federated forges (Coming soon!)

Federated DVCS Repository	Status	Issues	PRs	Wiki	CI	Discussions
🧪 galtzo-floss/turbo_tests2 on GitLab	The Truth	💚	💚	💚	🐭 Tiny Matrix	➖
🧊 galtzo-floss/turbo_tests2 on CodeBerg	An Ethical Mirror (Donate)	💚	💚	➖	⭕️ No Matrix	➖
🐙 galtzo-floss/turbo_tests2 on GitHub	Another Mirror	💚	💚	💚	💯 Full Matrix	💚
🎮️ Discord Server		Let's	talk	about	this	library!

Enterprise Support

Available as part of the Tidelift Subscription.

Need enterprise-level guarantees?

The maintainers of this and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use.

💡Subscribe for support guarantees covering all your FLOSS dependencies
💡Tidelift is part of Sonar
💡Tidelift pays maintainers to maintain the software you depend on!
📊@Pointy Haired Boss: An enterprise support subscription is "never gonna let you down", and supports open source maintainers

Alternatively:

✨ Installation

Install the gem and add to the application's Gemfile by executing:

bundle add turbo_tests2

If bundler is not being used to manage dependencies, install the gem by executing:

gem install turbo_tests2

⚙️ Configuration

turbo_tests2 ships the turbo_tests2 executable by default.

If you want an opt-in compatibility command for a specific project, generate a local shim:

$ bundle exec turbo_tests2 shim install
Installed turbo_tests shim at bin/turbo_tests.

That creates bin/turbo_tests, which delegates to bundle exec turbo_tests2 "$@". Remove it with:

$ bundle exec turbo_tests2 shim remove
Removed turbo_tests shim at bin/turbo_tests.

Create test databases

$ bundle exec turbo_tests2 --create

🔧 Basic Usage

Show help:

$ bundle exec turbo_tests2 -h
Usage: turbo_tests2 [options]

[optional] Only selected files & folders:
  turbo_tests2 spec/bar spec/baz/xxx_spec.rb

Options:
    -n, --count [PROCESSES]          How many processes to use, default: available CPUs
    -w, --workers [PROCESSES]        Alias for -n, --count
    -r, --require PATH               Require a file.
    -f, --format FORMATTER           Choose a formatter. Available formatters: progress (p), documentation (d). Default: progress
    -t, --tag TAG                    Run examples with the specified tag.
    -o, --out FILE                   Write output to a file instead of $stdout
        --runtime-log FILE           Location of previously recorded test runtimes
        --example-status-log FILE    Use RSpec example status persistence timings for grouping
        --pattern PATTERN            Run spec files matching this regex pattern
        --exclude-pattern PATTERN    Exclude spec files matching this regex pattern
        --only-group GROUP_INDEX[,GROUP_INDEX]
                                      Run only the selected 1-based parallel_tests group index(es)
        --group-by MODE              Group files by runtime, filesize, or found order
        --allowed-missing PERCENT    Allowed percentage of missing runtimes for runtime grouping
        --unknown-runtime SECONDS    Runtime in seconds to assign files missing runtime history
    -v, --verbose                    More output
        --worker-output MODE         Raw worker output mode: warnings, stream, buffered, or quiet; env: TURBO_TESTS2_WORKER_OUTPUT
        --fail-fast=[N]
        --seed SEED                  Seed for RSpec
        --order ORDER                RSpec example order: random (default) or defined
        --no-random                  Run examples in defined order without passing a seed
        --create                     Create databases
        --print_failed_group         Prints group that had failures in it
        --nice                       execute test commands with low priority

By default, turbo_tests2 generates one random RSpec seed, prints it, and passes that same seed to every worker process. Use --seed SEED to replay a run, or --order defined / --no-random when you want ordered examples without a seed.

turbo_tests2 supports selected parallel_tests options explicitly. It does not invoke the parallel_tests CLI directly, and it does not blindly pass unknown parallel_tests flags through after --. Options after -- are parsed only when listed as supported below.

To select or exclude files matching a regex:

bundle exec turbo_tests2 -n 4 --pattern spec/system
bundle exec turbo_tests2 -n 4 --exclude-pattern spec/system

The compatibility separator also accepts supported options:

bundle exec turbo_tests2 -n 4 -- --pattern spec/system
bundle exec turbo_tests2 -n 4 -- --exclude-pattern spec/system

To rerun one or more selected 1-based groups from a prior parallel split:

bundle exec turbo_tests2 -n 4 --only-group 2
bundle exec turbo_tests2 -n 4 -- --only-group 1,3

To choose a supported parallel_tests grouping mode explicitly:

bundle exec turbo_tests2 -n 4 --group-by runtime
bundle exec turbo_tests2 -n 4 --group-by filesize
bundle exec turbo_tests2 -n 4 --group-by found
bundle exec turbo_tests2 -n 4 -- --group-by runtime

runtime grouping uses the configured runtime log, which turbo_tests2 continues to record by default. filesize and found do not use runtime history for the initial split, but worker runtime recording still runs so future runtime-based runs can use the updated log.

Runtime grouping also supports the explicit parallel_tests tuning flags --allowed-missing PERCENT and --unknown-runtime SECONDS:

bundle exec turbo_tests2 -n 4 --group-by runtime --allowed-missing 25
bundle exec turbo_tests2 -n 4 --group-by runtime --unknown-runtime 0.5
bundle exec turbo_tests2 -n 4 -- --allowed-missing 25 --unknown-runtime 0.5

Selected group runs default to filesize grouping unless --group-by is provided.

Supported `parallel_tests` Options

`parallel_tests` option	Status	`turbo_tests2` equivalent	Notes
`-n`, `--count PROCESSES`	Supported natively	`-n`, `--count`; `-w`, `--workers` aliases	Parsed as a `turbo_tests2` option before any `--` separator.
`-p`, `--pattern PATTERN`	Supported	`--pattern PATTERN`	May be supplied before or after `--`; mapped to `parallel_tests` file discovery.
`--exclude-pattern PATTERN`	Supported	`--exclude-pattern PATTERN`	May be supplied before or after `--`; mapped to `parallel_tests` file discovery.
`--only-group GROUP_INDEX[,GROUP_INDEX]`	Supported	`--only-group GROUP_INDEX[,GROUP_INDEX]`	May be supplied before or after `--`; uses 1-based `parallel_tests` group indexes.
`--group-by runtime`	Supported	`--group-by runtime`	May be supplied before or after `--`; uses runtime-log grouping.
`--group-by filesize`	Supported	`--group-by filesize`	May be supplied before or after `--`; groups by file size.
`--group-by found`	Supported	`--group-by found`	May be supplied before or after `--`; keeps discovered file order.
`--allowed-missing PERCENT`	Supported	`--allowed-missing PERCENT`	May be supplied before or after `--`; validates `0..100`.
`--unknown-runtime SECONDS`	Supported	`--unknown-runtime SECONDS`	May be supplied before or after `--`; validates finite non-negative seconds.
`--runtime-log PATH`	Supported natively	`--runtime-log FILE`	Parsed as a `turbo_tests2` option before any `--` separator.
`--nice`	Supported natively	`--nice`	Parsed as a `turbo_tests2` option before any `--` separator.
`--fail-fast`	Supported natively	`--fail-fast[=N]`	Uses `turbo_tests2` fail-fast handling and RSpec worker arguments.
`--verbose`	Supported natively	`-v`, `--verbose`	Enables `turbo_tests2` verbose output.
`--test-options`, `-o`	Not supported as pass-through	Use `turbo_tests2` RSpec-facing flags	`turbo_tests2` exposes selected RSpec options directly, such as `--seed`, `--order`, `--no-random`, `--tag`, `--format`, and `--out`.
`--group-by default`, `steps`, `scenarios`	Not supported	None	`turbo_tests2` targets RSpec file grouping, not every `parallel_tests` framework mode.
`--single`, `--isolate`, `--isolate-n`	Not supported	None	No first-class mapping yet.
`--specify-groups`	Not supported	None	No first-class mapping yet.
`-m`, `--multiply-processes`	Not supported	None	Use an explicit `-n`/`--count` value.
`-e`, `--exec`, `--exec-args`, `--non-parallel`	Not supported	None	`turbo_tests2` runs RSpec workers, not arbitrary command groups.
`--suffix`, `--type`, `--ignore-tags`	Not supported	None	`turbo_tests2` currently targets RSpec.
`--serialize-stdout`, `--prefix-output-with-test-env-number`, `--combine-stderr`, `--quiet`, `--verbose-command`, `--verbose-process-command`, `--verbose-rerun-command`	Not supported	None	`turbo_tests2` owns worker output collection and formatter reporting.
`--no-symlinks`, `--allow-duplicates`, `--first-is-1`, `--highest-exit-status`, `--failure-exit-code`, `--test-file-limit`	Not supported	None	These need explicit design and tests before they can be accepted.

Worker Output Modes

Raw worker stdout/stderr is separate from the parent process formatter output. The progress dot parade is reconstructed from JSON formatter events and already streams from the parent process as workers report examples. Use --worker-output MODE, or TURBO_TESTS2_WORKER_OUTPUT=MODE, to choose how raw worker stdout/stderr is handled. A CLI flag takes precedence over the environment variable.

Mode	Behavior
`warnings`	Default. Buffer raw worker output, print warning/deprecation lines after successful runs, and print full buffered raw output on failures.
`stream`	Stream raw worker stdout/stderr immediately without enabling verbose command logging. Buffered output is not replayed at the end.
`buffered`	Buffer raw worker output and print all buffered output after the run completes.
`quiet`	Suppress raw worker output on successful runs. Failed runs still print buffered raw output.

Known coverage formatter chatter remains collapsed into the concise coverage summary.

turbo_tests2 supports custom formatter such as Fuubar, but you might need to require it:

bundle exec turbo_tests2 -r fuubar -f Fuubar spec/whatever

Rake Hooks

If Rake is present, the CLI will invoke the tasks turbo_tests2:setup and turbo_tests2:cleanup before and after running the test suite. These can be used to do work that should only happen once, such as removing files or collating coverage:

# lib/tasks/turbo_tests.rake
namespace :turbo_tests2 do
  task setup: :environment do
    # precompile assets once, to avoid doing it per each process
    Rake::Tasks["assets:precompile"]
  end

  task cleanup: :environment do
    # keep things nice and tidy
    Rake::Tasks["assets:clobber"]
  end
end

SimpleCov

You can get accurate coverage reporting by having SimpleCov write the results for each process into a different directory and then have the results collated as part of cleanup:

# spec/spec_helper.rb
require "simplecov"

# Configure minimum test coverage levels
#
# Details of default values for these configuration options can be seen at
# https://github.com/simplecov-ruby/simplecov/blob/master/lib/simplecov/profiles/rails.rb
SimpleCov.start("rails") do
  enable_coverage :branch

  coverage_dir "coverage/turbo_tests/#{ENV["TEST_ENV_NUMBER"]}"

  formatter SimpleCov::Formatter::SimpleFormatter
end

# lib/tasks/turbo_tests2.rake
namespace :turbo_tests2 do
  task setup: :environment do
    # remove any existing coverage files to avoid false reporting
    FileUtils.rm_rf("coverage/turbo_tests")
  end

  task cleanup: :environment do
    require "simplecov"

    # report coverage usage based on the results of all tests
    SimpleCov.collate(Dir["coverage/turbo_tests/*/.resultset.json"]) do
      enable_coverage :branch

      minimum_coverage line: 100, branch: 100
    end
  end
end

🦷 FLOSS Funding

While galtzo-floss tools are free software and will always be, the project would benefit immensely from some funding. Raising a monthly budget of... "dollars" would make the project more sustainable.

We welcome both individual and corporate sponsors! We also offer a wide array of funding channels to account for your preferences. Currently, Open Collective is our preferred funding platform.

If you're working in a company that's making significant use of galtzo-floss tools we'd appreciate it if you suggest to your company to become a galtzo-floss sponsor.

You can support the development of galtzo-floss tools via GitHub Sponsors, Liberapay, PayPal, Open Collective and Tidelift.

📍 NOTE
If doing a sponsorship in the form of donation is problematic for your company from an accounting standpoint, we'd recommend the use of Tidelift, where you can get a support-like subscription instead.

Open Collective for Individuals

Support us with a monthly donation and help us continue our activities. [Become a backer]

NOTE: kettle-readme-backers updates this list every day, automatically.

No backers yet. Be the first!

Open Collective for Organizations

Become a sponsor and get your logo on our README on GitHub with a link to your site. [Become a sponsor]

NOTE: kettle-readme-backers updates this list every day, automatically.

No sponsors yet. Be the first!

Another way to support open-source

I’m driven by a passion to foster a thriving open-source community – a space where people can tackle complex problems, no matter how small. Revitalizing libraries that have fallen into disrepair, and building new libraries focused on solving real-world challenges, are my passions. I was recently affected by layoffs, and the tech jobs market is unwelcoming. I’m reaching out here because your support would significantly aid my efforts to provide for my family, and my farm (11 🐔 chickens, 2 🐶 dogs, 3 🐰 rabbits, 8 🐈‍ cats).

If you work at a company that uses my work, please encourage them to support me as a corporate sponsor. My work on gems you use might show up in bundle fund.

I’m developing a new library, floss_funding, designed to empower open-source developers like myself to get paid for the work we do, in a sustainable way. Please give it a look.

Floss-Funding.dev: 👉️ No network calls. 👉️ No tracking. 👉️ No oversight. 👉️ Minimal crypto hashing. 💡 Easily disabled nags

🔐 Security

See SECURITY.md.

🤝 Contributing

If you need some ideas of where to help, you could work on adding more code coverage, or if it is already 💯 (see below) check issues or PRs, or use the gem and think about how it could be better.

We so if you make changes, remember to update it.

See CONTRIBUTING.md for more detailed instructions.

🚀 Release Instructions

See CONTRIBUTING.md.

Code Coverage

Coverage service badges

🪇 Code of Conduct

Everyone interacting with this project's codebases, issue trackers, chat rooms and mailing lists agrees to follow the .

🌈 Contributors

Made with contributors-img.

Also see GitLab Contributors: https://gitlab.com/galtzo-floss/turbo_tests2/-/graphs/main

⭐️ Star History

📌 Versioning

This library follows for its public API where practical. For most applications, prefer the Pessimistic Version Constraint with two digits of precision.

For example:

spec.add_dependency("turbo_tests2", "~> 3.0")

📌 Is "Platform Support" part of the public API? More details inside.

Dropping support for a platform can be a breaking change for affected users. If a release changes supported platforms, it should be called out clearly in the changelog and versioned with that impact in mind.

To get a better understanding of how SemVer is intended to work over a project's lifetime, read this article from the creator of SemVer:

"Major Version Numbers are Not Sacred"

See CHANGELOG.md for a list of releases.

📄 License

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

© Copyright

See LICENSE.md for the official copyright notice.

🤑 A request for help

Maintainers have teeth and need to pay their dentists. After getting laid off in an RIF in March, and encountering difficulty finding a new one, I began spending most of my time building open source tools. I'm hoping to be able to pay for my kids' health insurance this month, so if you value the work I am doing, I need your support. Please consider sponsoring me or the project.

To join the community or get help 👇️ Join the Discord.

To say "thanks!" ☝️ Join the Discord or 👇️ send money.

💌 💌 💌

Please give the project a star ⭐ ♥.

Many parts of this project are actively managed by a kettle-jem smart template utilizing StructuredMerge.org merge contracts.

Thanks for RTFM. ☺️

Field	Value
Package	turbo_tests2
Description	🚀 turbo_tests2`is an RSpec parallel test runner built on`parallel_tests`. It uses` parallel_tests`for process counts, file grouping, and runtime balancing, then replaces interleaved worker output with incremental summarized RSpec reporting. Source code of`turbo_test2` gem is based on Discourse and Rubygems work in this area (see README.md).
Homepage	https://github.com/galtzo-floss/turbo_tests2
Source	https://github.com/galtzo-floss/turbo_tests2
License	`MIT`
Funding	https://github.com/sponsors/pboling, https://ko-fi.com/pboling, https://liberapay.com/pboling/donate, https://opencollective.com/galtzo-floss, https://thanks.dev/u/gh/pboling, https://tidelift.com/funding/github/rubygems/turbo_tests2, https://www.buymeacoffee.com/pboling