react-native/docs/Contributing.md

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React Native is one of Facebook's first open source projects that is both under very active development and is also being used to ship code to everybody using Facebook's mobile apps. We're still working out the kinks to make contributing to this project as easy and transparent as possible, but we're not quite there yet. Hopefully this document makes the process for contributing clear and preempts some questions you may have.

• Code of Conduct
• Development Process
• Branch Organization
• How to Get in Touch
• Bugs
• Pull Requests
• Triaging Issues and Pull Requests
• Style Guide
• License

Code of Conduct

Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.

Our Development Process

Some of the core team will be working directly on GitHub. These changes will be public from the beginning. Other changesets will come via a bridge with Facebook's internal source control. This is a necessity as it allows engineers at Facebook outside of the core team to move fast and contribute from an environment they are comfortable in.

Branch Organization

We will do our best to keep master in good shape, with tests passing at all times. But in order to move fast, we will make API changes that your application might not be compatible with. We will do our best to communicate these changes and version appropriately so you can lock into a specific version if need be.

To see what changes are coming and provide better feedback to React Native contributors, use the latest release candidate when possible. By the time a release candidate is released, the changes it contains will have been shipped in production Facebook apps for over two weeks.

How to Get in Touch

Many React Native users are active on Stack Overflow. If you want to get a general sense of what React Native folks talk about, check out the React Native Community Facebook group. There is also an active community of React and React Native users on the Discord chat platform in case you need help.

The React Native team sends out periodical updates through the following channels:

• React Native Blog
• @ReactNative on Twitter

Core contributors to React Native meet monthly and post their meeting notes on the React Native blog. You can also find ad hoc discussions in the React Native Core Contributors Facebook group.

Bugs

Where to Find Known Issues

We are using GitHub Issues for our public bugs. Before filing a new task, try to make sure your problem doesn't already exist.

Questions and feature requests are tracked elsewhere:

• Have a question? Ask on Stack Overflow.
• If you have a question regarding future plans, check out the roadmap.
• Have a feature request that is not covered in the roadmap? Add it here.

Reporting New Issues

When opening a new issue, always make sure to fill out the issue template. This step is very important! Not doing so may result in your issue getting closed. Don't take this personally if this happens, and feel free to open a new issue once you've gathered all the information required by the template.

• One issue, one bug: Please report a single bug per issue.
• Provide a Snack: The best way to get attention on your issue is to provide a reduced test case. You can use Snack to demonstrate the issue.
• Provide reproduction steps: List all the steps necessary to reproduce the issue. Provide a Snack or upload a sample project to GitHub. The person reading your bug report should be able to follow these steps to reproduce your issue with minimal effort.
• Try out the latest version: Verify that the issue can be reproduced locally by updating your project to use React Native from master. The bug may have already been fixed!

We're not able to provide support through GitHub Issues. If you're looking for help with your code, consider asking on Stack Overflow or reaching out to the community through other channels.

Security Bugs

Facebook has a bounty program for the safe disclosure of security bugs. With that in mind, please do not file public issues; go through the process outlined on that page.

Pull Requests

Your First Pull Request

Working on your first Pull Request? You can learn how from this free video series:

How to Contribute to an Open Source Project on GitHub

We have a list of beginner friendly issues to help you get your feet wet in the React Native codebase and familiar with our contribution process. This is a great place to get started.

If you decide to fix an issue, please be sure to check the comment thread in case somebody is already working on a fix. If nobody is working on it at the moment, please leave a comment stating that you intend to work on it so other people don't accidentally duplicate your effort.

If somebody claims an issue but doesn't follow up for more than two weeks, it's fine to take over it but you should still leave a comment.

Sending a Pull Request

If you send a pull request, please do it against the master branch. We maintain stable branches for stable releases separately but we don't accept pull requests to them directly. Instead, we cherry-pick non-breaking changes from master to the latest stable version.

The core team will be monitoring for pull requests. When we get one, we'll run some Facebook-specific integration tests on it first. From here, we'll need to get another person to sign off on the changes and then merge the pull request. For API changes we may need to fix internal uses, which could cause some delay. We'll do our best to provide updates and feedback throughout the process.

Small pull requests are much easier to review and more likely to get merged. Make sure the PR does only one thing, otherwise please split it.

Before submitting a pull request, please make sure the following is done…

1. Fork the repository and create your branch from master.
2. Add the copyright notice to the top of any new files you've added.
3. Describe your test plan in your commit.
4. Ensure tests pass on both Travis and Circle CI.
5. Make sure your code lints (npm run lint).
6. If you haven't already, sign the CLA.

Note: It is not necessary to keep clicking Merge master to your branch on the PR page. You would want to merge master if there are conflicts or tests are failing. The Facebook-GitHub-Bot ultimately squashes all commits to a single one before merging your PR.

Test plan

A good test plan has the exact commands you ran and their output, provides screenshots or videos if the pull request changes UI or updates the website.

• If you've added code that should be tested, add tests!
• If you've changed APIs, update the documentation.
• If you've updated the docs, verify the website locally and submit screenshots if applicable (see website/README.md)

See What is a Test Plan? to learn more.

Continuous integration tests

Make sure all tests pass on both Travis and Circle CI. PRs that break tests are unlikely to be merged.

You can learn more about running tests and contributing to React Native next.

Breaking changes

When adding a new breaking change, follow this template in your pull request:

### New breaking change here

- **Who does this affect**:
- **How to migrate**:
- **Why make this breaking change**:
- **Severity (number of people affected x effort)**:

If your pull request is merged, a core contributor will update the list of breaking changes which is then used to populate the release notes.

Copyright Notice for files

Copy and paste this to the top of your new file(s):

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

If you've added a new module, add a @providesModule <moduleName> at the end of the comment. This will allow the haste package manager to find it.

Contributor License Agreement (CLA)

In order to accept your pull request, we need you to submit a CLA. You only need to do this once, so if you've done this for another Facebook open source project, you're good to go. If you are submitting a pull request for the first time, just let us know that you have completed the CLA and we can cross-check with your GitHub username.

Complete your CLA here: https://code.facebook.com/cla

Proposing a change

If you intend to change the public API, or make any non-trivial changes to the implementation, we recommend filing an issue. This lets us reach an agreement on your proposal before you put significant effort into it.

If you're only fixing a bug, it's fine to submit a pull request right away but we still recommend to file an issue detailing what you're fixing. This is helpful in case we don't accept that specific fix but want to keep track of the issue.

Triaging Issues and Pull Requests

One great way you can contribute to the project without writing any code is to help triage issues and pull requests as they come in. Ask for more information if the issue does not provide all the details required by the template. Suggest labels. Flag issues that are stale or that should be closed. Ask for test plans and review code.

Adding labels, closing and reopening issues, and merging pull requests is, as you may expect, limited to a subset of contributors. Simply commenting on the issue or pull request can still go a long way towards helping us keep the number of outstanding issues under control.

Using the Facebook GitHub Bot

The Facebook GitHub Bot allows certain active members of the community to perform administrative actions such as labeling and closing issues. The list of community members with this kind of access can be found at the top of IssueCommands.txt. The bot can be triggered by adding any of the following commands as a standalone comment on an issue:

@facebook-github-bot no-template

Use this when more information is needed, especially if the issue does not adhere to the issue template. The bot will close the issue after adding the "Needs more information" label.

@facebook-github-bot stack-overflow

Mark issues that do not belong in the bug tracker, and redirect to Stack Overflow. The bot will close the issue after adding the "For Stack Overflow" label.

@facebook-github-bot needs-repro

Prompts the author to provide a reproducible example or Snack. The bot will apply the "Needs more information" label.

@facebook-github-bot cannot-repro

Use this when the issue cannot be reproduced, either because it affects a particular app but no minimal repro was provided, or the issue describes something sporadic that is unlikely to be reproduced by a community member. The bot will close the issue.

@facebook-github-bot duplicate (#[0-9]+)

Marks an issue as a duplicate. Requires a issue number to be provided. The bot will close the issue.

@facebook-github-bot label (.*)

Use this command to add a label, such as "iOS" or "Android", to an issue.

@facebook-github-bot feature

Use this when an issue describes a feature request, as opposed to a reproducible bug. The bot will point the author to the feature request tracker, add the "Feature Request" label, then close the issue.

@facebook-github-bot expected

Use this when an issue describes a type of expected behavior. The bot will close the issue.

@facebook-github-bot answered

Use this when an issue appears to be a question that has already been answered by someone on the thread. The bot will close the issue.

@facebook-github-bot close

Closes an issue without providing a particular explanation.

@facebook-github-bot reopen

Re-opens a previously closed issue.

@facebook-github-bot bugfix

Mark issues that describe a reproducible bug and encourage the author to send a pull request. The bot will add the "Help Wanted" label.

@facebook-github-bot no-reply

Use this when an issue requires more information from the author but they have not added a comment in a while. The bot will close the issue.

@facebook-github-bot icebox

Use this when an issue has been open for over 30 days with no activity and no community member has volunteered to work on a fix. The bot will close the issue after adding the "Icebox" label.

Additionally, the following commands can be used on a pull request:

@facebook-github-bot cla

Remind the author that the CLA needs to be signed.

@facebook-github-bot shipit

Flag the PR for merging. If used by a core contributor, the bot will attempt to import the pull request. In general, core contributors are those who have consistently submitted high quality contributions to the project.

Style Guide

Our linter will catch most styling issues that may exist in your code. You can check the status of your code styling by simply running npm run lint.

However, there are still some styles that the linter cannot pick up.

Code Conventions

General

• Most important: Look around. Match the style you see used in the rest of the project. This includes formatting, naming things in code, naming things in documentation.
• Add trailing commas,
• 2 spaces for indentation (no tabs)
• "Attractive"

JavaScript

• Use semicolons;
• 'use strict';
• Prefer ' over "
• Do not use the optional parameters of setTimeout and setInterval
• 80 character line length

JSX

• Prefer " over ' for string literal props
• When wrapping opening tags over multiple lines, place one prop per line
• {} of props should hug their values (no spaces)
• Place the closing > of opening tags on the same line as the last prop
• Place the closing /> of self-closing tags on their own line and left-align them with the opening <

Objective-C

• Space after @property declarations
• Brackets on every if, on the same line
• - method, @interface, and @implementation brackets on the following line
• Try to keep it around 80 characters line length (sometimes it's just not possible...)
• * operator goes with the variable name (e.g. NSObject *variableName;)

Java

• If a method call spans multiple lines closing bracket is on the same line as the last argument.
• If a method header doesn't fit on one line each argument goes on a separate line.
• 100 character line length

Documentation

• Do not wrap lines at 80 characters - configure your editor to soft-wrap when editing documentation.

License

By contributing to React Native, you agree that your contributions will be licensed under its BSD license.

What Next?

Read the next section to learn how to test your changes.