We welcome contributions from the community. This doc describes the process to contribute patches and the general guidelines we expect contributors to follow.

Communication

• Before starting work on a major feature, please reach out to us via GitHub, Slack, email, etc. We will make sure no one else is already working on it and ask you to open a GitHub issue.
• A "major feature" is defined as any change that is > 100 LOC altered (not including tests), or changes any user-facing behavior. We will use the GitHub issue to discuss the feature and come to agreement. This is to prevent your time being wasted, as well as ours.
• Small patches and bug fixes don't need prior communication.
• Some good tasks to get started with are available in the issue tracker.

Release cadence

• Currently we are targeting approximately quarterly official releases. We may change this based on customer demand.
• In general, master is assumed to be release candidate quality at all times for documented features. For undocumented or clearly under development features, use caution or ask about current status when running master. Stripe runs master in production, typically deploying every week.
• We currently provide binary packages available via releases page.

Writing Documentation

Documentation improvements are very welcome. The source of sorbet.org is located in website/ in the tree.

Testing

• Our CI runs all tests with UBSan and ASan. You can run them locally by passing --config=sanitize when running tests.
• We expect all assumptions made when writing code to be spelled explicitly via ENFORCE(myAssumption); statements.
• Some characteristics of good tests:
  • includes comments: what is being tested and why?
  • be minimal, deterministic, stable (unaffected by irrelevant changes), easy to understand and review
  • have minimal dependencies: a typechecker bug test should not depend on, e.g. the Ruby standard library

Submitting a PR

• Create small PRs that are narrowly focused on addressing a single concern. We often receive PRs that are trying to fix several things at a time, but if only one fix is considered acceptable, nothing gets merged and both author's & review's time is wasted. Create more PRs to address different concerns and everyone will be happy.
• Bug fixes should include regression tests -- in the same commit as the fix. If testing isn't feasible, the commit message should explain why.
• New features and enhancements must be motivated by adding common usage as tests. Please reach out to the team on the #internals channel of the sorbet-slack before starting on new features.
• Follow the Boy Scout Rule: "Always leave the code behind in a better state than you found it"
• We will not merge any PR that is not passing tests.
• Your PR description should have details on what the PR does. If it fixes an existing issue it should end with "Fixes #XXX".
• When all of the tests are passing and all other conditions described herein are satisfied, a maintainer will be assigned to review and merge the PR.
• We expect that once a PR is opened, it will be actively worked on until it is merged or closed. We reserve the right to close PRs that are not making progress (no changes for 7 days), or that include functionality the core team isn't aligned on supporting. PRs that are closed due to lack of activity can be reopened later. Closing stale PRs helps us to keep on top of all of the work currently in flight.
• Please consider joining the sorbet-slack.

PR review policy for maintainers

• We try to turn around reviews within one week, though sometimes we slip up. If you feel like your PR has gotten lost and it's been open for more than a week, please reach out on the #internals channel on the sorbet-slack.
• It is generally expected that at least a single maintainer should review every PR.
• If there is a question on who should review a PR please discuss in Slack.
• Anyone is welcome to review any PR that they want, whether they are a maintainer or not.
• As PR's are merged, they are tested against Stripe internal codebase and are pushed in squashed form to GitHub.
• Please clean up the title and body before merging. By default, our merge bot fills the squash merge title with the original title, and the commit body with every individual commit from the PR.