The web-platform-tests Project
The web-platform-tests Project is a cross-browser test suite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software that is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.
The most important sources of information and activity are:
- github.com/web-platform-tests/wpt: the canonical location of the project's source code revision history and the discussion forum for changes to the code
- web-platform-tests.org: the documentation website; details how to set up the project, how to write tests, how to give and receive peer review, how to serve as an administrator, and more
- wpt.live: a public deployment of the test suite, allowing anyone to run the tests by visiting from an Internet-enabled browser of their choice
- wpt.fyi: an archive of test results collected from an array of web browsers on a regular basis
- Real-time chat room: the
IRC chat room named
#testingon irc.w3.org; includes participants located around the world, but busiest during the European working day; all discussion is archived here
- Mailing list: a public and low-traffic discussion list
- RFCs: a repo for requesting comments on substantial changes that would impact other stakeholders or users; people who work on WPT infra are encouraged to watch the repo.
If you'd like clarification about anything, don't hesitate to ask in the chat room or on the mailing list.
Setting Up the Repo
Clone or otherwise get https://github.com/web-platform-tests/wpt.
Note: because of the frequent creation and deletion of branches in this
repo, it is recommended to "prune" stale branches when fetching updates,
git pull --prune (or
git fetch -p && git merge).
Running the Tests
Command Line Tools
wpt command provides a frontend to a variety of tools for
working with and running web-platform-tests. Some of the most useful
wpt serve- For starting the wpt http server
wpt run- For running tests in a browser
wpt lint- For running the lint against all tests
wpt manifest- For updating or generating a
wpt install- For installing the latest release of a browser or webdriver server on the local machine.
wpt serve-wave- For starting the wpt http server and the WAVE test runner. For more details on how to use the WAVE test runner see the documentation.
wpt commands must be prefixed with
python or the path
to the python binary (if
python is not in your
python wpt [command]
Alternatively, you may also use
Bash on Ubuntu on Windows
in the Windows 10 Anniversary Update build, then access your windows
partition from there to launch
Please make sure git and your text editor do not automatically convert
line endings, as it will cause lint errors. For git, please set
git config core.autocrlf false in your working tree.
The master branch is automatically synced to http://w3c-test.org/.
Pull requests are
automatically mirrored except those
that modify sensitive resources (such as
.py). The latter require
someone with merge access to comment with "LGTM" or "w3c-test:mirror" to
indicate the pull request has been checked.
Save the Web, Write Some Tests!
Absolutely everyone is welcome to contribute to test development. No test is too small or too simple, especially if it corresponds to something for which you've noted an interoperability bug in a browser.
The way to contribute is just as usual:
- Fork this repository (and make sure you're still relatively in sync with it if you forked a while ago).
- Create a branch for your changes:
git checkout -b topic.
- Make your changes.
./wpt lintas described above.
- Commit locally and push that to your repo.
- Create a pull request based on the above.
Issues with web-platform-tests
If you spot an issue with a test and are not comfortable providing a pull request per above to fix it, please file a new issue. Thank you!