1589006 - Add API to Talos/DAMP to execute script in content processes

Status: NEW

(DevTools :: General, task, P3)

Description

[Julian Descottes [:jdescottes]]

DevTools performance tests (DAMP) are currently using MessageManager in order to run test scripts in the content page.

When we will be able to write Fission scenarios (blocked on Bug 1583914), we should also have an API that can execute scripts in the remote iframes.

To remain consistent with other test suites, it would be great to either reuse SpecialPowers.spawn, or if it's not possible at least make the API identical.

Comment 1

[Julian Descottes [:jdescottes]]

Kris, any suggestion here? Do you think integrating SpecialPowers with Talos is doable (and would not impact the tests performance). Or should we rather write something custom for Talos (maybe sharing bits with SpecialPowers where relevant).

Thanks.

Comment 2

[Chris Peterson [:cpeterson]]

Enabling Talos is a prerequisite for enabling Fission in Nightly (M6).

Comment 3

[Julian Descottes [:jdescottes]]

I was playing around with adding SpecialPowers to talos in order to directly reuse SpecialPowers.spawn.

I loaded it by adding '${talos}/../../specialpowers' to the list of extensions loaded when running DAMP [1]. After that we can get SpecialPowers actors during DAMP tests, but as soon as SpecialPowers tries to load testing-common dependencies (in my case at https://searchfox.org/mozilla-central/rev/131338e5017bc0283d86fb73844407b9a2155c98/testing/specialpowers/content/SpecialPowersChild.jsm#1699), the operation fails.

I don't think we'll want to load to many test modules in talos, but we will still need to provide a feature similar to SpecialPowers.spawn, and we will most likely have to create a new set of JsWindowActors for that.

[1] https://searchfox.org/mozilla-central/rev/131338e5017bc0283d86fb73844407b9a2155c98/testing/talos/talos/test.py#451

Comment 4

[Mike Conley (:mconley) (:⚙️)]

It looks like we, at run time, generate a chrome.manifest file to register the testing-common resources here, at least for mochitests: https://searchfox.org/mozilla-central/rev/652014ca1183c56bc5f04daf01af180d4e50a91c/testing/mochitest/runtests.py#1302-1304

I'm not opposed to making these sorts of things available in Talos (they'd probably make writing certain things much easier), however, it's important that we avoid overhead and secondary effects from these modules during the measurement windows.

Comment 5

[Mike Conley (:mconley) (:⚙️)]

Perhaps a logical place to register the testing-common stuff is here within the talos-powers extension:

https://searchfox.org/mozilla-central/rev/652014ca1183c56bc5f04daf01af180d4e50a91c/testing/talos/talos/talos-powers/api.js#387

Comment 6

[Chris Peterson [:cpeterson]]

dt-fission-reserve bugs do not need to block Fission Nightly (M6).

Comment 7

[Chris Peterson [:cpeterson]]

Tracking dt-fission-reserve bugs for Fission MVP until we know whether they really need to block Fission or not.

Comment 8

[Kris Maglione [:kmag]]

Loading SpecialPowers for DAMP specifically might be OK, but I'd be reluctant to load it for talos tests in general, since it's pretty heavyweight and would interfere with things like page load metrics.

I'd lean towards just adding the functionality you need to talos-powers, and probably using SpecialPowersSandbox.jsm for the bits you can.

Comment 9

[Chris Peterson [:cpeterson]]

Moving old "dt-fission-reserve" bugs to "dt-fission-future" because they don't block Fission MVP.