This document provides instructions for becoming a contributor to the GWT (Google Web Toolkit) open source project. It outlines the process for signing the contributor license agreement, setting up the necessary tools like Git and Gerrit, contributing code changes by submitting pull requests through GitHub, and ensuring code style guidelines are followed. The workflow for contributing changes to both the GWT codebase and documentation site is described.

1. Become a GWT contributor

2. Introduction
- All GWT is under the Apache 2.0 license.
- Everybody is welcome to improve it, but
must sign a CLA.
- You need to be familiar with git

3. Resources
- Users mailing list.
- Contributors mailing list.
- GWT project site and documentation
- Gitter channel
- Google+ channel
- Stackoverflow QA

4. Preparation: Gerrit
- Check that you already have an account
in github: https://github.com/join
- Sign in into the GWT gerrit service:
https://gwt-review.googlesource.com
- Gerrit will use your gmail account

5. Sign a CLA
- It works for both gerrit (gwt) and github (gwt-site)
- Click on your name, then click on settings.
- Fill everything even your github id

6. Clone tools, gwt, and gwt-site repos

7. Architecture of GWT project
- Source code: git repository.
- Compilation tools: git repository.
- Review: gerrit
- Continuous integration: Jenkins
- Site & Doc: github

8. Contributing to gwt-site

9. Google Bot
http://gwtproject.org
Browser
Edit
check CLA
merge
Github
Desktop
publish
Contributing gwt-site markdown
user/gwt-site gwtproject/gwt-site
discussion
fork
pull request
Continuous
Integration
Jenkins
Discuss
WebSite

10. Google Bot
http://gwtproject.org
Browser
clone/pull/push
check CLA
project
merge
Github
Desktop
publish
Contributing gwt-site assets
user/gwt-site gwtproject/gwt-site
discussion
fork
pull request
Continuous
Integration
Jenkins
Discuss
WebSite

11. How to make the contributions
- GWT site uses markdown
- Visit the site and click on edit icon
- Fork the repo if not already done
- Follow github flavored syntax.
- You can mix HTML syntax but, do only in
the case there is no markdown equivalent
- Send a github pull-request
- Wait for feedback
- Merge

12. Send the Pull Request 4 clicks
1 2
3 4

13. - Wait for feedback
- Make suggested modifications in
github
- A contributor will Merge when done
- Will be live in gwtproject.org after few
minutes
Follow github discussions

14. Contributing to gwt

15. Central maven
repository
Git Repository
patches
Git Repository
master
Review System
Continuous
Integration
Jenkins
Cloned to github
Browser
clone pull
push
verify+1
project
merge
review+2
snapshot
Git Repository
tools (github)
clone
Gerrit
Desktop
IDE
Contributing GWT workflow

16. Setting up git
Set your UserName and Email
Configure the gerrit commit hook

17. Setting up git
Try your first commit

18. Setting up git
Obtain your HTTP cookie

19. Setting up git
Save your cookie
& push your first commit !!!

20. Contributing to code
- You need to be familiar with ‘ant’
- Compile the code
- Run checkstyle & tests
- Prepare your IDE
- Plugins
- Formating & checkstyle rules
- Import projects in your IDE
- Run checkstyle & tests from your IDE

21. Contributing to code
- Check that the issue is in the issues list
- Work in a new local branch
- Make changes and add Tests
- Run tests
- Commit & push changes
- Make sure git is configured: name, email, hook
- Add issue numbers to commit message
- Wait for review
- amend & rebase until ready
- Merge

22. Using your IDE
Choose whatever development environment
you are comfortable with.
- Eclipse:
- Work through the eclipse/README.txt
- IntelliJ IDEA:
- Style configuration
- Gradle build

23. - Select or create an issue.
- It’s recommended that any patch was previously
documented in an issue ticket in github
- Search for:
- status:patcheswelcome or status:accepted
- Issue reporting guidelines
Contributing, how to start

24. - Javadoc: classes and public methods.
- Class structure and member sorting
(relaxed)
- Indentation: 2 spaces
- Imports: remove unused, follow order
- Line length: 100 chars
- Meaningful names.
Contributing, Style rules

25. Contributing, how to use ‘ant’
- Check Code Compiles
$ ant clean dist-dev [2min]
- Check Styles
$ ant checkstyle apicheck [3min - 1min]
- Check Tests Compile
$ ant compile.tests [1min - 15secs]
- Run certain Tests
$ ( cd dev && ant test )
$ ( cd user && ant test.nongwt )

26. - Create a new branch
$ git checkout -b issue_name
- Commit your changes
$ git commit -a -m 'Message, Bug: issue nnn'
- Push for Review
$ git push origin HEAD:refs/drafts/master #push as private draft
$ git push origin HEAD:refs/for/master #public ready for review
- New changes
$ git commit --amend --no-edit -a
$ git push origin HEAD:refs/for/master
Contributing, how to use ‘git’
Tip: use different branches for different and unrelated changes
Tip: push as draft to check your changes in gerrit and not being public yet

27. Dealing with gerrit
- Check your patch in gerrit until it looks ok to you
(avoid noise, follow rules)
- Assign a reviewer to your patch, check the
maintainer list for candidates.
- Use gerrit for discussions
- Make the proposed changes
- Amend the previous commit
- Repeat the process until you get a +2
- Merge on master (rebase can be needed)
Tip: contribute reviewing other contributors’ patches

28. Promote draft > review
Abandon a Change
Add a reviewer
Vote a Review
Contributing: using ‘gerrit’

29. Thanks for contributing
GWT
manolo@vaadin.com