Call minutes - December 13th 11AM PST (Triage)

On Wed, Dec 12, 2018 at 2:42 PM Yoav Weiss <yoav@yoav.ws> wrote:

> Heya folks!
>
> Please join us on the call this Thursday. I plan to discuss the missing
> pieces in getting us to ship long-standing specs, but feel free to add
> things you want to discuss to the agenda
> <https://docs.google.com/document/d/10dz_7QM5XCNsGeI63R864lF9gFqlqQD37B4q8Q46LMM/edit?pli=1#heading=h.ohc3prc50j0w>
> .
>
>
>    -
>
>    Resource Timing
>    -
>
>       should redirected navigations have a workerStart value if a
>       previous redirect URL was intercepted
>       <https://github.com/w3c/resource-timing/issues/118>
>       -
>
>       spec what requestStart, responseStart, and responseEnd should
>       represent when service worker is involved
>       <https://github.com/w3c/resource-timing/issues/119>
>       -
>
>       Many of the tests are flaky
>       <https://github.com/w3c/resource-timing/issues/182>
>       -
>
>       Add a note regarding negative timestamps for navigation preload
>       requests <https://github.com/w3c/resource-timing/pull/183>
>       -
>
>    User Timing
>    -
>
>       What’s blocking shipping? (WPT results
>       <https://wpt.fyi/results/user-timing?label=experimental>)
>       -
>
>    Navigation Timing
>    -
>
>       WPT results
>       <https://wpt.fyi/results/navigation-timing?label=experimental>
>
>
> Cheers :)
>

Thanks all for joining!
Minutes from the call are now here
<https://docs.google.com/document/d/e/2PACX-1vTbdw8vAyajirbambMWZTh7_EgSwMAw--kKM_ihkr0YnHlXZEPJpudGkpn3LaRKsdnsu0Pfg1804i6a/pub>
.

Copied here for safe keeping:
WebPerfWG call minutes - Dec 13 2018
Participants

Todd Reifsteck, Ilya Grigorik, Markus Stange, Steve Souders, Charlie Vazac,
Nic Jansma, Phil Walton, Nicolas Pena, Tim Dresser, Yoav Weiss

Scribe: Charlie Vazac

Chair: Yoav Weiss
Admin

Next call: Thu Jan 10th, 3p EST

Yoav: plan to experiment with auto-captioning the calls.

First step - record the calls! Are people ok with that?

Todd: we probably need to ask about recording the meetings on each call,
for new members

Ilya: value in recording whether transcription is good or not
Resource Timingshould redirected navigations have a workerStart value if a
previous redirect URL was intercepted
<https://www.google.com/url?q=https://github.com/w3c/resource-timing/issues/118&sa=D&ust=1544737182302000>

Yoav: workerStart only refers to last intercept, or it’s under defined as
to which worker workerStart should refer to, if there are multiple workers
involved. Also, workerStart probably needs to be gated by TAO.

Example: intercept first navigation from one servicer worker that forwards
to another origin which has its own sw.

Ilya: first sw triggers 301?

Yoav: yes, that’s what Ben is saying

Ilya: i’ll have to look, but this should be covered, because we should
restart processing on 301

Nicolas: agrees that it should/does reset

Yoav: Ben is saying that the tests don’t assert the right thing - not in
sync. There are two issues: workerStart gated by TAO (is no-brainer) and
validating that the tests are enforcing the spec.

Yoav: we agree that we should enforce current dfn of “last redirect”? Has
thought it would be meaningful to accumulate workerStarts, but that’s
probably outside of the current model.

Todd: redirects are handled by fetch spec, we hand wave that we record the
“last one”...

Nicolas: redirects happen in step 20

Yoav: step 20 (20.1?) should also set workerStart to 0

Yoav: any volunteers to fix this one?

crickets…

AI - Nicolas to file chrome bug that will fix the test that is incorrect
spec what requestStart, responseStart, and responseEnd should represent
when service worker is involved
<https://www.google.com/url?q=https://github.com/w3c/resource-timing/issues/119&sa=D&ust=1544737182306000>

Yoav: there are many issues where the current spec is under specified, many
of these timers require fetch integration, postponed to L3, perhaps this
one should be moved to L3 as well? Objections?

Nic: let’s punt to L3

Ilya: for L2, we could specify requestStart and responseEnd (when renderer
receives last byte). For L2, all things that sw does is opaque to us, and
we can specify it as such

Todd: we scoped out what the sw does. fetchStart/workerStart nuances (for
redirects) - need careful review.

AI - Yoav to untangle this one, defer some parts to L3, maybe create some
new L2 blockers.

Ilya: for L2, treat sw as blackbox excepting workerStart, with no viz into
what’s happening inside
Many of the tests are flaky
<https://www.google.com/url?q=https://github.com/w3c/resource-timing/issues/182&sa=D&ust=1544737182308000>

Yoav: this is a recent issue, wpt infra team is starting to look at test
flakiness, including one of yours Nic.

Nic: i will take a look at initiatorType test flakiness

Yoav: i will look at the re-parenting one

Yoav: another flaky test in UT

Nicolas: I will take a look at the flaky UT test

Yoav: here are all the flaky tests
<https://www.google.com/url?q=https://github.com/web-platform-tests/wpt/pull/14409%23issuecomment-445753408&sa=D&ust=1544737182309000>

Add a note regarding negative timestamps for navigation preload requests
<https://www.google.com/url?q=https://github.com/w3c/resource-timing/pull/183&sa=D&ust=1544737182310000>

Yoav: this is in PR, can someone PTAL? This will close an outstanding
issue. We are down to 9 actual issues. 2 are _almost_ closed.

Yoav: Issue 87 is adding tests about first-byte measurements. Tests were
added, merge was blocked by flakiness, Andrew is taking a look at that. I
have many buffer-full-* tests that are also blocked on flakiness. In the
next few weeks, we can close all of these L2 issues. There are a few around
networking, but they are tough to test. We can change the spec easily,
tough to test, best path forward is to file issues on WPT infra folks (120,
160, 123?). Can you test multiple sites with same cert? Plan is to fix
spec, file issues for tests that aren’t possible. 123 might be testable.
User TimingMark-measure-return-null.html
<https://www.google.com/url?q=https://github.com/web-platform-tests/wpt/commit/a4efb68eb4bb30453a6c958ad58f8c2540dc967e&sa=D&ust=1544737182311000>

Nicolas: We added a test to ensure that mark()/measure() do not return
anything, because in L3 they do/will return the mark/measure. At present,
it’s returning NULL - not undefined. So the test is wrong, will pass in
Chrome - failing elsewhere (even though they match spec). I propose we drop
the test in advance of L3

Tim: should we fix Chrome and then fix the tests?

Yoav: this is testing behavior that changes from L2 to L3?

Nicolas: that’s right, this won’t make sense for L3. IMP the idlharness
could/should handle the return value being undefined.

Todd: the test should test L2 or L3, shouldn’t be deleted / changed.

Nicolas: test is not correct atm, does it make sense to keep it now in
light of L3 coming down

…

Yoav: we should rename the test to make it clear that it’s for L2

Ilya: first patch for L3 will have to delete that test

Nicolas: this shouldn’t matter much - i don't think we should block L3 for
this test

Ilya: the way the test was written, it’s for L2 support feature detection

Nicolas: that shouldn’t be necessary, that’s what idlharness should do

Ilya: from dev. perspective, how do I check L2 versus L3? Are there other
ways?

Philip: there needs to be a proper way to detect it

Ilya: two things: rework test for better feature detection (also add how to
do this in spec) AND we need to update current spec so it passes….

[this is about feature detection for L2 v L3]

Philip: maybe we can check the prototype of the entry, see what’s exposed
on there. If performance.mark returns an object, and it has a prototype,
you can check to see if “details” is there.

Yoav: can’t we re-write this test to feature detect and then test L2 OR L3
(based on what the feature detection tells you)?

Tim: we have clear action item
What’s blocking shipping? (WPT results
<https://www.google.com/url?q=https://wpt.fyi/results/user-timing?label%3Dexperimental&sa=D&ust=1544737182314000>
)

Yoav: so what’s blocking shipping of UT from L2 to rec? 3 issues. There are
3 tests that are failing in chrome. First one is fixed, others are on their
way to be fixed, right Nicolas?

Nicolas: not sure, those are recent tests….

Yoav: possible time gap between tests landing and impl’s landing

Nicolas: tests arrive immediately, but dev build doesn’t have impl bits

Yoav: who’s next closest impl? Probably firefox. It’s failing the
mark/measure, but that’s a test issue. Failing another, but that’s a recent
addition.

Markus: AI to open up bugs on firefox re supported types.

Yoav: and we need to fix the test to feature detect and test L2 or test L3,
whatever’s there.

Yoav: once impl’s land, and …. We should be able to ship to rec. Other
blockers?

Todd: supported types is not supported in any other browser, right? Which
is part of the Perf Timeline spec.

Yoav: each spec is calling into perf timeline to register

Todd: I think these are L3 tests

Nicolas: unclear on how branching works, do we get to pick a commit to
split L2 v L3?

Yoav/Tim: yes.

Todd: I suggest we move on with what we agreed about for L2 (which excludes
supported types)

Tim: what do we need to do wrt spec for shipping L2

Nicolas: branch called “L2”, change … to “CR”

Todd: but we published L2 in July, it’s already in CR

Nicolas: so we need to point the branch to *that* commit

Yoav: not trivial to find branch point, but we can probably find it.

Nicolas: let’s use the last commit from … particular day

Todd: let’s also take minor editorial changes (until 10/17) - let’s use
that as our L2. and now we’re on to L3!

Yoav: if testing canary, we are there except for mark/measure returning
null/undefined
Navigation TimingWPT results
<https://www.google.com/url?q=https://wpt.fyi/results/navigation-timing?label%3Dexperimental&sa=D&ust=1544737182319000>

Yoav: it looks like Firefox is second greenest, but there are still a few
failures

Markus - AI to triage, file issues against these failures
<https://www.google.com/url?q=https://wpt.fyi/results/navigation-timing?label%3Dexperimental&sa=D&ust=1544737182320000>

Yoav: we aren’t blocked on those tests, but let’s file bugs and get to green

Todd: half of the failures are passing in nightly

Markus: should that be reflected in experimental?

Everyone: it should, but :shrug:

Markus: Regarding the supported entry type tests, should they only be for
L3?
Yoav: we still need to fix them… per perf-timeline L2 spec (and L2 of NT),
It’s L3 in UT, because L2 of UT shipped beforehand.