Want to contribute? Great! First, read this page (including the small print).
Pull requests can be hard to review if they try to tackle too many things at once. Phabricator's "Writing Reviewable Code" provides a set of guidelines that help increase the likelihood of your pull request getting merged.
In short (slightly modified from the original article):
- A pull request should be as small as possible, but no smaller.
- The smallest a pull request can be is a single cohesive idea: don't make pull requests so small that they are meaningless on their own.
- Turn large pull requests into small pull requests by dividing large problems into smaller problems and solving the small problems one at a time.
- Write sensible pull request descriptions.
Our additions:
- A pull request should affect as few components as possible.
- Pull requests must include a modification to the CHANGELOG.md summarizing the change.
This repository follows a file layout convention that ensures consistency and predictability across all of our components. The conventions are described in the GOS-conventions repository.
Before we can use your code, you must sign the Google Individual Contributor License Agreement (CLA), which you can do online. The CLA is necessary mainly because you own the copyright to your changes, even after your contribution becomes part of our codebase, so we need your permission to use and distribute your code. We also need to be sure of various other things—for instance that you'll tell us if you know that your code infringes on other people's patents. You don't have to sign the CLA until after you've submitted your code for review and a member has approved it, but you must do it before we can put your code into our codebase. Before you start working on a larger contribution, you should get in touch with us first through the issue tracker with your idea so that we can help out and possibly guide you. Coordinating up front makes it much easier to avoid frustration later on.
All submissions, including submissions by project members, require review. We allow pull requests to be filed, but we perform code reviews on codereview.cc.
Contributions made by corporations are covered by a different agreement than the one above, the Software Grant and Corporate Contributor License Agreement.
This checklist describes the process by which Material components are built.
API reviews work like typical code reviews with the added constraint of only reviewing the component's public APIs.
To initiate an API review, send a pull request that only includes the public APIs you wish to review.
TODO(featherless): Flesh this out with some concrete examples of existing API reviews.
The work: avoid non-essential dependencies.
The why: the team has had many discussions on this topic. Generally speaking, we use the following considerations as a basis for minimizing dependencies:
- dependencies increase cost of maintenance and cost of usage for a component, and
- dependency-less components are much easier to drop in and, most importantly, to remove from a project.
Reach out to the team directly for advice or questions on this matter.
Recommendations:
- Aim for zero non-platform dependencies.
- Reasonable exceptions can be made, but must be justified.
- Do not create "Core" or "Utility" libraries.
The work: add nullability annotations to every header of your component.
The why: nullability annotations improve Swift usage of a component's APIs. Learn more
Recommendations:
We explicitly annotate all public APIs rather than use NS_ASSUME_NONNULL_BEGIN. This is an
intentional deviation from Apple’s practice of using the ASSUME macros.
While Xcode 7 also introduced _Nullable and _Nonnull, we require the __nullable and
__nonnull versions in order to maintain Xcode 6 support.
Further reading: