Add multiple tests for prefetch behavior #35707

noamr · 2022-08-30T17:13:46Z

See whatwg/html#8111 (comment)

Tests that:

preload/prefetch-cache.html
No 5 minute rule (cache headers must be respected)
preload/prefetch-document.html
No special treatment of as=document
Whether Accept is left as its default value.
Storage partitioning is applied, including for documents
preload/prefetch-load-event.html
Does not block the load event
preload/prefetch-headers.html
Sec-Purpose and Sec-Destination are correct
preload/prefetch-types.html
Always uses prefetch destination, and ignores as=""
preload/prefetch-events.html
Load & error events are fired, and invalid/empty hrefs are ignored.

domenic

Really great stuff.

Can we also test (or maybe tests already exist?) the behavior for empty string href="" and unparseable URL href=""?

Can we test that these never fire load/error events on the <link> element?

preload/prefetch-headers.html

domenic · 2022-09-05T03:10:44Z

preload/prefetch-load-event.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<title>Ensures that prefetch respects cache headers</title>


Wrong title. You can omit the <title> if there's only a single test, to avoid these sorts of mismatches.

noamr · 2022-09-05T14:29:17Z

Can we test that these never fire load/error events on the <link> element?

Seems like they are fired. Will amend the spec PR

domenic · 2022-09-06T01:00:06Z

We still need tests that as="asdf" causes the fetch to not go through (since it leads to https://whatpr.org/html/8111/links.html#link-type-prefetch step 3 setting request to null and thus step 4 returning early).

preload/prefetch-events.html

noamr · 2022-09-06T05:00:54Z

We still need tests that as="asdf" causes the fetch to not go through (since it leads to https://whatpr.org/html/8111/links.html#link-type-prefetch step 3 setting request to null and thus step 4 returning early).

Oh I think as is completely ignored. I'll amend it in the spec and add a test.

noamr · 2022-09-06T06:03:08Z

We still need tests that as="asdf" causes the fetch to not go through (since it leads to https://whatpr.org/html/8111/links.html#link-type-prefetch step 3 setting request to null and thus step 4 returning early).

Oh I think as is completely ignored. I'll amend it in the spec and add a test.

I changed the spec, prefetch overrides the options destination instead of the request destination, so as is practically ignored.

preload/prefetch-cache.html

preload/prefetch-document.html

domenic · 2023-01-17T01:06:54Z

preload/prefetch-document.html

+    return await get_prefetch_info(href);
+}
+
+async function test_prefetch_document({origin, as}, expected) {


I think this helper is more confusing than helpful. I'd suggest inlining it.

Hmm, I meant the test_prefetch_document helper being confusing... the prefetch_document helper is fine.

preload/prefetch-headers.html

preload/prefetch-types.html

domenic · 2023-01-17T01:12:11Z

preload/prefetch-cache.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>


I wonder if all these files should go in https://github.com/web-platform-tests/wpt/tree/master/html/semantics/links/linktypes instead? Not sure, and I guess it's OK either way...

domenic · 2023-01-17T07:08:37Z

preload/prefetch-document.html

+    return await get_prefetch_info(href);
+}
+
+async function test_prefetch_document({origin, as}, expected) {


Hmm, I meant the test_prefetch_document helper being confusing... the prefetch_document helper is fine.

See whatwg/html#8111 (comment) Tests that: * preload/prefetch-cache.html No 5 minute rule (cache headers must be respected) * preload/prefetch-document.html No special treatment of as=document Whether Accept is left as its default value. Storage partitioning is applied, including for documents * preload/prefetch-load-event.html Does not block the load event * preload/prefetch-headers.html Whether any additional headers (Sec-Purpose, Purpose, X-moz, X-Purpose) are sent (depending on what we put in the spec) * preload/prefetch-types.html Always uses prefetch destination, and ignores as=""

Co-authored-by: Domenic Denicola <d@domenic.me>

This replaces the existing `Purpose: prefetch` and `x-moz: prefetch` headers. Tests: web-platform-tests/wpt#35707. Part of whatwg/html#8111. Closes w3c/webappsec-fetch-metadata#84 and w3c/resource-hints#74. Co-authored-by: Anne van Kesteren <annevk@annevk.nl>

domenic · 2023-01-17T12:01:18Z

I guess prefetch-cache.html is flaky in Firefox, maybe because Firefox prioritizes prefetches low and so sometimes it does the prefetch, sometimes it doesn't? Is there any easy fix for this to make it fail deterministically in Firefox, or should we ask for an admin-merge?

noamr · 2023-01-17T12:31:12Z

I guess prefetch-cache.html is flaky in Firefox, maybe because Firefox prioritizes prefetches low and so sometimes it does the prefetch, sometimes it doesn't? Is there any easy fix for this to make it fail deterministically in Firefox, or should we ask for an admin-merge?

It's not the reason for the flakiness. The test waits until the prefetch is performed.
What's flaky is the reliance on particular behavior of the HTTP cache, which can decide to empty at any moment :(
Perhaps I can run it in a loop 10 times and even a single success is good enough

domenic · 2023-01-17T12:49:47Z

Eh, I doubt Firefox is clearing the HTTP cache more aggressively. More likely is that it has some bug where it doesn't actually make the value available until the next page load, or something like that... It's especially suspicious that we had exactly 5/10.

noamr · 2023-01-18T05:03:54Z

Eh, I doubt Firefox is clearing the HTTP cache more aggressively. More likely is that it has some bug where it doesn't actually make the value available until the next page load, or something like that... It's especially suspicious that we had exactly 5/10.

Ok perhaps we should admin merge this and let Mozilla deal with prefetch flakiness in their implementation...

domenic · 2023-01-18T05:29:04Z

/cc @web-platform-tests/admins for help admin-merging this. Firefox's flakiness seems to be due to genuinely inconsistent implementation; Noam has tried several workarounds with no luck.

wpt-pr-bot added preload wg-webperf labels Aug 30, 2022

wpt-pr-bot assigned snuggs Aug 30, 2022

wpt-pr-bot requested review from snuggs and yoavweiss August 30, 2022 17:13

noamr mentioned this pull request Aug 30, 2022

Define link processing for prefetch whatwg/html#8111

Merged

3 tasks

noamr removed the request for review from yoavweiss August 30, 2022 17:17

domenic reviewed Sep 5, 2022

View reviewed changes

domenic reviewed Sep 6, 2022

View reviewed changes

preload/prefetch-events.html Outdated Show resolved Hide resolved

noamr mentioned this pull request Sep 6, 2022

Accept header for prefetch whatwg/fetch#1485

Merged

3 tasks

noamr mentioned this pull request Jan 10, 2023

Send Sec-Purpose: prefetch header for prefetch requests whatwg/fetch#1576

Merged

4 tasks

domenic reviewed Jan 17, 2023

View reviewed changes

domenic approved these changes Jan 17, 2023

View reviewed changes

noamr and others added 8 commits January 17, 2023 10:18

Add tests for load/error events

776db0a

Add cross-origin event tests

a82d865

Test for proprietary headers

3fd2122

Add test cases for cross-origin error events

0b2ca17

Update preload/prefetch-cache.html

b5d5398

Co-authored-by: Domenic Denicola <d@domenic.me>

Fix CR comments

15acb49

Clean up doc test

d9c6b07

noamr force-pushed the prefetch-2 branch from 071c7cc to d9c6b07 Compare January 17, 2023 08:20

Retries in cache test

bae2c62

Use script instead of fetch to de-flake firefox

68192f7

sideshowbarker merged commit 1423a32 into master Jan 18, 2023

sideshowbarker deleted the prefetch-2 branch January 18, 2023 06:35

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add multiple tests for prefetch behavior #35707

Add multiple tests for prefetch behavior #35707

noamr commented Aug 30, 2022 •

edited

Loading

domenic left a comment

domenic Sep 5, 2022

noamr commented Sep 5, 2022

domenic commented Sep 6, 2022

noamr commented Sep 6, 2022

noamr commented Sep 6, 2022

domenic Jan 17, 2023

domenic Jan 17, 2023

domenic Jan 17, 2023

domenic Jan 17, 2023

domenic commented Jan 17, 2023

noamr commented Jan 17, 2023 •

edited

Loading

domenic commented Jan 17, 2023

noamr commented Jan 18, 2023

domenic commented Jan 18, 2023

		@@ -0,0 +1,14 @@
		<!DOCTYPE html>
		<title>Ensures that prefetch respects cache headers</title>

Add multiple tests for prefetch behavior #35707

Add multiple tests for prefetch behavior #35707

Conversation

noamr commented Aug 30, 2022 • edited Loading

domenic left a comment

Choose a reason for hiding this comment

domenic Sep 5, 2022

Choose a reason for hiding this comment

noamr commented Sep 5, 2022

domenic commented Sep 6, 2022

noamr commented Sep 6, 2022

noamr commented Sep 6, 2022

domenic Jan 17, 2023

Choose a reason for hiding this comment

domenic Jan 17, 2023

Choose a reason for hiding this comment

domenic Jan 17, 2023

Choose a reason for hiding this comment

domenic Jan 17, 2023

Choose a reason for hiding this comment

domenic commented Jan 17, 2023

noamr commented Jan 17, 2023 • edited Loading

domenic commented Jan 17, 2023

noamr commented Jan 18, 2023

domenic commented Jan 18, 2023

noamr commented Aug 30, 2022 •

edited

Loading

noamr commented Jan 17, 2023 •

edited

Loading