commit f7650d12f0ab5b38b6dd8572599c280d702ad42c
parent 9d85c195d43edb5e8e1e6015b401653902862751
Author: Kurt Catti-Schmidt <kschmi@microsoft.com>
Date: Mon, 10 Nov 2025 22:18:47 +0000
Bug 1997460 [wpt PR 55779] - [CSS Modules] Bypass fetch for Blob URL's, a=testonly
Automatic update from web-platform-tests
[CSS Modules] Bypass fetch for Blob URL's
After switching to Blob URL's in CL:7075691, I noticed that the fetched
stylesheet is not always available immediately in a fully declarative
scenario (where both the style tag is a module and
shadowrootadoptedstylesheets references it), which wasn't the case for
dataURI's. Typically, the first n fetches fail to fetch, where n is
random.
I discovered that dataURI's were always synchronously returned from
ResourceFetcher via CreateResourceForStaticData.
To match this behavior with Blob URL's, this CL immediately creates a
module map entry for a <style type="module"> upon parsing. This entry
can then be immediately queried when referenced from the
`shadowrootadoptedstylesheets` attribute, avoiding a fetch entirely.
DataURI's still need a fetch to generate the underlying object.
A test was added that failed ~50% of the time without this change.
Bug: 448174611
Change-Id: If50701981f7eaa138fff7d9ca799431c3303fa72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7093679
Commit-Queue: Kurt Catti-Schmidt <kschmi@microsoft.com>
Reviewed-by: Mason Freed <masonf@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1541305}
--
wpt-commits: 20e711cb9291d4e15fe8a600218306e59f163110
wpt-pr: 55779
Diffstat:
1 file changed, 37 insertions(+), 0 deletions(-)
diff --git a/testing/web-platform/tests/shadow-dom/declarative/tentative/shadowrootadoptedstylesheets/shadowrootadoptedstylesheets-with-declarative-module.html b/testing/web-platform/tests/shadow-dom/declarative/tentative/shadowrootadoptedstylesheets/shadowrootadoptedstylesheets-with-declarative-module.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<title>shadowrootadoptedstylesheets with Declarative CSS Module</title>
+<meta name="author" title="Kurt Catti-Schmidt" href="mailto:kschmi@microsoft.com" />
+<link rel='help' href='https://github.com/whatwg/html/pull/11687'>
+<script src='/resources/testharness.js'></script>
+<script src='/resources/testharnessreport.js'></script>
+
+<style type="module" specifier="foo">
+span {color:blue}
+</style>
+
+<div id="host">
+ <template shadowrootmode="open" shadowrootadoptedstylesheets="foo">
+ <span id="test_element">Test content</span>
+ </template>
+</div>
+
+<script>
+ const host = document.getElementById("host");
+ test(function (t) {
+ assert_equals(
+ host.shadowRoot.adoptedStyleSheets.length,
+ 1,
+ "The shadowrootadoptedstylesheets will declaratively import named specifiers into the adoptedStyleSheets array.",
+ );
+
+ }, "adoptedStyleSheets is populated from a <template> element's shadowrootadoptedstylesheets attribute.");
+ const test_element = host.shadowRoot.getElementById("test_element");
+
+ test(function (t) {
+ assert_equals(getComputedStyle(test_element)
+ .color, "rgb(0, 0, 255)",
+ "Declarative styles were applied.");
+
+ }, "Styles from the adoptedStyleSheets are applied to elements.");
+</script>
+\ No newline at end of file
