This folder contains the web platform tests and the code required to integrate them with Servo. To learn how to write tests, go here.
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.run.py
: run the web-platform-tests in Servo.web-platform-tests
: copy of the web-platform-tests.metadata
: expected failures for the web-platform-tests we run.mozilla
: web-platform-tests that cannot be upstreamed.
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.
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 all the WPT tests with debug mode results in a lot of timeout.
If one wants to run all the tests,
build with mach build -r
and
test with mach test-wpt --release
When avoiding mach
for some reason, one can run run.py
directly. However, this requires that all the dependencies for
wptrunner
are avaliable in the current python environment.
(See also the relevant section of the upstream README.)
It can be useful to run a test without the interference of the test runner, for
example when using a debugger such as gdb
.
To do this, first add 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
Then, navigate to tests/wpt/web-platform-tests
. Next, create a directory,
e.g. local-resources/
, to contain a local copy of the
resources/testharnessreport.js
file. The version in the repository is
actually a Python format string that has substitution done on it by
harness/wptrunner/environment.py
to configure test output. Then, place a
modified copy of the testharnessreport.js
file in that directory, removing
the format string variable:
mkdir local-resources
cp resources/testharnessreport.js local-resources/
$EDITOR local-resources/testharnessreport.js
# Replace `output:%(output)d` with `output:1` or `output:0`.
Now create a configuration file at config.json
for the web-platform-tests
server (configuration options you don't specify will be loaded from the
defaults at config.default.json
) with the following contents:
{"aliases": [
{"url-path": "/resources/testharnessreport.js",
"local-dir": "local-resources"
}
]
}
Finally, you can run python serve
from tests/wpt/web-platform-tests
.
Then navigate Servo to http://web-platform.test:8000/path/to/test
.
When working with tests, you may want to compare Servo's result with Firefox.
You can supply --product firefox
along with the path to a Firefox binary (as
well as few more odds and ends) to run tests in Firefox from your Servo
checkout:
GECKO="$HOME/projects/mozilla/gecko"
GECKO_BINS="$GECKO/obj-firefox-release-artifact/dist/Nightly.app/Contents/MacOS"
./mach test-wpt dom --product firefox --binary $GECKO_BINS/firefox --certutil-binary $GECKO_BINS/certutil --prefs-root $GECKO/testing/profiles
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
The simplest way to create a new test is to use the following command:
./mach create-wpt tests/wpt/path/to/new/test.html
This will create test.html in the appropriate directory using the WPT template for JavaScript tests. Tests are written using testharness.js. Documentation can be found here. To create a new reference test instead, use the following:
./mach create-wpt --reftest tests/wpt/path/to/new/reftest.html --reference tests/wpt/path/to/reference.html
reference.html
will be created if it does not exist, and reftest.html
will be created using the WPT reftest template. To know more about reftests, check this.
These new tests can then be run in the following manner like any other WPT test:
./mach test-wpt tests/wpt/path/to/new/test.html
./mach test-wpt tests/wpt/path/to/new/reftest.html
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.
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 mozilla
directory contains tests that cannot be upstreamed for some
reason (e.g. because they depend on Servo-specific APIs), as well as some
legacy tests that should be upstreamed at some point. When run they are
mounted on the server under /_mozilla/
.
Reftest results can be analyzed from a raw log file. To generate this run
with the --log-raw
option e.g.
./mach test-wpt --log-raw wpt.log
This file can then be fed into the reftest analyzer which will show all failing tests (not just those with unexpected results). Note that this ingests logs in a different format to original version of the tool written for gecko reftests.
The reftest analyzer allows pixel-level comparison of the test and reference
screenshots. Tests that both fail and have an unexpected result are marked
with a !
.
MANIFEST.json can be regenerated automatically with the mach command update-manifest
e.g.
./mach update-manifest
This is equivalent to running
./mach test-wpt --manifest-update SKIP_TESTS