commit | d06a8c42054a1c333172b69a0486508f573bab9d | [log] [tgz] |
---|---|---|
author | Rune Lillesveen <futhark@chromium.org> | Tue Apr 28 21:52:42 2020 |
committer | Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> | Tue Apr 28 22:30:17 2020 |
tree | 53bd3e2809d6fc16cd4a9b3b4ad849c1e669fad7 | |
parent | c9dcc5b1a4a6418cc91a2aee462fc15d0838be88 [diff] |
Element moving between shadow-trees for no-op between lifecycles. FlatTreeNodeData is cleared on insertion so that nodes moving between shadow trees do not keep stale parent information since we use the FlatTreeNodeData ancestor to mark ancestors style dirty without updating the slot assignment. This is normally fine since inserting a child node of a shadow host will mark the host for slot re-assignment, and the slot re-assignment will update FlatTreeNodeData accordingly. The diffing of flat tree children in NotifySlottedNodesOfFlatTreeChange will mark the inserted node for style recalc via FlatTreeParentChanged. There is however a glitch which can happen if a node is removed from a shadow host, inserted into a different node, and then moved back into the original shadow host without having any re-slotting happening in between. If the node ends up in the same flat tree position, we will not be able to detect that it needs FlatTreeParentChanged to be marked for style recalc. Example: <div id="host"> <:shadow-root> <slot></slot> </:shadow-root> <span>PASS</span></div> <div id="other"></div> <script> // Make everything clean. FlatTreeNodeData ancestor for the span is // the slot. host.offsetTop; let slotted = host.querySelector("span"); // The span is removed, the layout object is detached, and the // ComputedStyle is cleared. slotted.remove(); // Insert span into the #other element, FlatTreeNodeData for the span // is cleared. The host is marked for slot re-assignment. other.appendChild(slotted); // The span is re-added as a child of #host, but nothing is marked // style dirty since the #host has a shadow root and the span is not // yet part of the flat tree. host.appendChild(slotted); // Slot re-assignment happens, but the result of slotting is the same // as for the last lifecycle update, and nothing is marked dirty. That // results in the span not getting a ComputedStyle nor a LayoutObject. host.offsetTop; </script> The solution is currently to do a FlatTreeParentChanged for the case where we: 1. Already have a FlatTreeNodeData. 2. The FlatTreeNodeData ancestor is null before the slot assignments. 3. The node is assigned to a slot. It is definitely correct and necessary that we call FlatTreeParentChanged in this case, but we end up doing it twice for other elements which were added to the host, which used to be a child of another host (FlatTreeNodeData being non-null), and will also have FlatTreeParentChanged being called in the diffing as well. The question is if that will cause perf regressions, typically in microbenchmarks. Bug: 1072475 Change-Id: I5e697570b74599b0a3e01ca869eac022105fc6b9 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2160930 Commit-Queue: Rune Lillesveen <futhark@chromium.org> Reviewed-by: Mason Freed <masonfreed@chromium.org> Cr-Commit-Position: refs/heads/master@{#763537}
The web-platform-tests Project is a cross-browser test suite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software that is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.
The most important sources of information and activity are:
#testing
on irc.w3.org; includes participants located around the world, but busiest during the European working day; all discussion is archived hereIf you'd like clarification about anything, don't hesitate to ask in the chat room or on the mailing list.
Clone or otherwise get https://github.com/web-platform-tests/wpt.
Note: because of the frequent creation and deletion of branches in this repo, it is recommended to “prune” stale branches when fetching updates, i.e. use git pull --prune
(or git fetch -p && git merge
).
See the documentation website and in particular the system setup for running tests locally.
The wpt
command provides a frontend to a variety of tools for working with and running web-platform-tests. Some of the most useful commands are:
wpt serve
- For starting the wpt http serverwpt run
- For running tests in a browserwpt lint
- For running the lint against all testswpt manifest
- For updating or generating a MANIFEST.json
test manifestwpt install
- For installing the latest release of a browser or webdriver server on the local machine.On Windows wpt
commands must be prefixed with python
or the path to the python binary (if python
is not in your %PATH%
).
python wpt [command]
Alternatively, you may also use Bash on Ubuntu on Windows in the Windows 10 Anniversary Update build, then access your windows partition from there to launch wpt
commands.
Please make sure git and your text editor do not automatically convert line endings, as it will cause lint errors. For git, please set git config core.autocrlf false
in your working tree.
The master branch is automatically synced to http://w3c-test.org/.
Pull requests are automatically mirrored except those that modify sensitive resources (such as .py
). The latter require someone with merge access to comment with “LGTM” or “w3c-test:mirror” to indicate the pull request has been checked.
In the vast majority of cases the only upstream branch that you should need to care about is master
. If you see other branches in the repository, you can generally safely ignore them.
Save the Web, Write Some Tests!
Absolutely everyone is welcome to contribute to test development. No test is too small or too simple, especially if it corresponds to something for which you've noted an interoperability bug in a browser.
The way to contribute is just as usual:
git checkout -b topic
../wpt lint
as described above.If you spot an issue with a test and are not comfortable providing a pull request per above to fix it, please file a new issue. Thank you!