servo/tests/wpt/README.md

This folder contains the web platform tests, CSS WG tests, and the code required to integrate them with Servo.

Contents

In particular, this folder contains:

• config.ini: some configuration for the web-platform-tests.
• include.ini: the subset of web-platform-tests we currently run.
• config_css.ini: some configuration for the CSSWG tests.
• include_css.ini: the subset of the CSSWG tests we currently run.
• run_wpt.py glue code to run the web-platform-tests in Servo.
• run_css.py glue code to run the CSSWG tests in Servo.
• run.py common code used by run_wpt.py and run_css.py.
• web-platform-tests: copy of the web-platform-tests.
• metadata: expected failures for the web-platform-tests we run.
• css-tests copy of the built CSSWG tests.
• metadata-css expected failures for the CSSWG tests we run.

Running the tests

The simplest way to run the web-platform-tests in Servo is ./mach test-wpt in the root directory. This will run the subset of JavaScript tests defined in include.ini and log the output to stdout.

Similarly the CSSWG tests can be run using ./mach test-css.

A subset of tests may be run by providing positional arguments to the mach command, either as filesystem paths or as test urls e.g.

./mach test-wpt tests/wpt/web-platform-tests/dom/historical.html

to run the dom/historical.html test, or

./mach test-wpt dom

to run all the DOM tests.

There are also a large number of command line options accepted by the test harness; these are documented by running with --help.

Running the tests without mach

When avoiding mach for some reason, one can run either run_wpt.py ir run_css.py directly. However, this requires that all the dependencies for wptrunner are avaliable in the current python environment.

Running the tests manually

It can be useful to run a test without the interference of the test runner, for example when using a debugger such as gdb. In that case, start the server by first adding the following to the system's hosts file:

127.0.0.1   www.web-platform.test
127.0.0.1   www1.web-platform.test
127.0.0.1   www2.web-platform.test
127.0.0.1   web-platform.test
127.0.0.1   xn--n8j6ds53lwwkrqhv28a.web-platform.test
127.0.0.1   xn--lve-6lad.web-platform.test

and then running python serve from tests/wpt/web-platform-tests. Then navigate Servo to http://web-platform.test:8000/path/to/test.

Updating test expectations

When fixing a bug that causes the result of a test to change, the expected results for that test need to be changed. This can be done manually, by editing the .ini file under the metadata folder that corresponds to the test. In this case, remove the references to tests whose expectation is now PASS, and remove .ini files that no longer contain any expectations.

When a larger number of changes is required, this process can be automated. This first requires saving the raw, unformatted log from a test run, for example by running ./mach test-wpt --log-raw /tmp/servo.log. Once the log is saved, run from the root directory:

./mach update-wpt /tmp/servo.log

For CSSWG tests a similar prcedure works, with ./mach test-css and ./mach update-css.

Editing tests

web-platform-tests may be edited in-place and the changes committed to the servo tree. These changes will be upstreamed when the tests are next synced.

For CSS tests this kind of in-place update is not possible because the tests have a build step before they are pulled into the servo repository. Therefore corrections must be submitted directly to the source repository.

Updating the upstream tests

In order to update the tests from upstream use the same mach update commands. e.g. to update the web-platform-tests:

./mach update-wpt --sync
./mach test-wpt --log-raw=update.log
./mach update-wpt update.log

This should create two commits in your servo repository with the updated tests and updated metadata. The same process works for the CSSWG tests, using the update-css and test-css mach commands.

Updating the test harness

The easiest way to update the test harness is using git:

cd tests/wpt/harness
git init .
git remote add origin https://github.com/w3c/wptrunner
git fetch origin
git checkout master origin/master
cd ../../..

At this point you should commit the updated files in the servo git repository.