# Service Worker Performance Tests

Our performance tests are mochitests running in the [mozperftest](https://firefox-source-docs.mozilla.org/testing/perfdocs/mozperftest.html)
harness. Tests reside under {searchfox}`dom/serviceworkers/test/performance`,
itemized in perftest.toml. Beyond the standard mochitest machinery,
performance tests define a `perfMetadata` variable at the top level, and call:

`info("perfMetrics", JSON.stringify(metrics));`

to report their results, where *metrics* is a map from testpoint name to scalar
numeric value. See the [performance scripts documentation](https://firefox-source-docs.mozilla.org/testing/perfdocs/writing.html#mochitest)
for more.

They can be run via mach perftest, or as normal mochitests via mach test.
(Currently we can’t run the full manifest, see [bug 1865852](https://bugzilla.mozilla.org/show_bug.cgi?id=1865852).)

## Adding new tests

Add files to {searchfox}`perftest.toml <dom/serviceworkers/test/performance/perftest.toml>`
as usual for mochitests.

Modify linux.yml, macosx.yml, and windows11.yml under {searchfox}`taskcluster/kinds/perftest`.
Currently, each test needs to be added individually to the run command ({searchfox}`here <mozilla-central/rev/91cc8848427fdbbeb324e6ca56a0d08d32d3c308:taskcluster/ci/perftest/linux.yml#121-149>`,
for example). kind.yml can be ignored–it provides some defaults.

Add your new test to {searchfox}`perfdocs/config.yml <python/mozperftest/perfdocs/config.yml>`.

Modify the generated documentation using:

`$ ./mach lint -l perfdocs . --fix --warnings --outgoing`

There's currently a [bug](https://bugzilla.mozilla.org/show_bug.cgi?id=1872613)
which will likely cause the command to fail. Running it a second time should
succeed.

## Profiler Markers

Profiler markers can be used to collect timing data. Markers of known name can be inspected from the perftest. AUTO_PROFILER_MARKER_UNTYPED must be used, as we need both the start-time and end-time of the marker. For example:

```cpp
AUTO_PROFILER_MARKER_UNTYPED("interesting thing #1", DOM, {};
AUTO_PROFILER_MARKER_UNTYPED("interesting thing #2", DOM, {});
```

can be inspected from the perftest:

```js
await startProfiler();
interestingThings();
let pdata = await stopProfiler();
let duration_ms = inspectProfile(pdata, [
    "interesting thing #1",
    "interesting thing #2"
]);
```

## Staging tests in try jobs

`$ ./mach try fuzzy --full`

Look for `‘service-worker` to find things like:

perftest-windows-service-worker

perftest-macosx-service-worker

perftest-linux-service-worker

## Results

Results can be found in treeherder on [mozilla-central](https://treeherder.mozilla.org/jobs?repo=mozilla-central&searchStr=perftest)
and [autoland](https://treeherder.mozilla.org/jobs?repo=autoland&searchStr=perftest). Look
for linux-sw, macosx-sw, and win-sw ([example](https://treeherder.mozilla.org/perfherder/graphs?series=mozilla-central,4967140,1,15&selected=4967140,1814245176)).
These symbol names are defined in the .yml files under taskcluster/kinds/perftest.

## Contacts

DOM LWS

[Gregory Mierzwinski](https://people.mozilla.org/p/sparky)

 (Performance Tools)