Open-sourcing Sorbet: a fast, powerful type checker for Ruby

We’re excited to announce that Sorbet is now open source and you can try it today. Sorbet is a fast, powerful type checker designed for Ruby. It scales to codebases with millions of lines of code and can be adopted incrementally.

We designed Sorbet to be used at Stripe, where the vast majority of our code is written in Ruby. We’ve spent the last year and a half developing and adopting Sorbet internally, and we’re finally confident that Sorbet is not just an experimental, internal project—we’re ready to share Sorbet with the entire Ruby community. In fact, we’ve had more than 30 companies beta test Sorbet and provide feedback.

Today’s release includes:

• The core static type checker
• Tooling to create new Sorbet projects
• Tooling to gradually adopt Sorbet in existing projects
• A runtime DSL for writing type annotations
• A central repository for sharing type definitions for Ruby gems

… and much more. We’re excited for you to play around with Sorbet, integrate it into your codebases, and share your feedback. We’ve received immeasurable value from the Ruby community already: this is our way of giving back.

Getting started

We’ve put together a number of resources to help you get started with Sorbet:

• Adopting Sorbet: In just a few quick steps, get started using the Sorbet gem to type check an existing codebase.

• Gradual Type Checking : Sorbet is a gradual type checker. What does that mean, and how can we use it to our advantage?

• Docs: Check out the documentation to learn all about Sorbet’s features.

For a round-up of recent changes you can read State of Sorbet for Spring 2019 . And of course, feel free to browse the source on GitHub to learn how to build Sorbet, read the source code, report bugs, and contribute fixes!

Community

We know that releasing an open-source project is the just the first step, and we’re excited to continue building Sorbet with our community. Stripe is committed to growing the Sorbet project as a robust part of the Ruby ecosystem. Here’s how you can ask questions, report bugs, and share your experience reports:

• Ask us questions on Stack Overflow : We’ll be actively monitoring Stack Overflow questions with the sorbet tag, where you can ask questions you have while adopting Sorbet in your codebase.

• Chat with us on Slack : We’ve been using Slack to communicate with collaborators and beta testers; you can join our community to chat with other Sorbet users.

• Report issues on GitHub : Sorbet is still very young—if you find and can reproduce bugs in Sorbet, please share them!

Acknowledgements

Sorbet is the product of a large community of supporters , and we’re deeply appreciative for their work. You can see the complete list of contributors who helped us in the process of open sourcing Sorbet. And of course, we’d also like to thank the dozens of beta testers who braved the rough edges of Sorbet in its early days. :tada: