Bug 1888988 [wpt PR 45457] - Fix <meta> post-insertion steps expect…

…ations, a=testonly

Automatic update from web-platform-tests
Fix `<meta>` post-insertion steps expectations

See whatwg/html#10241 for the recommendation
to change these test expectations to align with Chromium and WebKit's
behavior.

FWIW, I did try and change the processing of these kinds of meta tags
in Chromium to use the insertion steps [1], and without any extra work
at least, this caused a bunch of crashes [2].

So this change (changing the test expectations) is easier, and aligns
with more browsers.

[1]: https://crrev.com/c/5399060
[2]: https://crbug.com/330694762

R=nrosenthal@chromium.org

Bug: 40150299, 330694762
Change-Id: I60f8ba556984bc1e8df4ba6e1dc375b1dfb7823d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5410497
Reviewed-by: Noam Rosenthal <nrosenthal@chromium.org>
Commit-Queue: Dominic Farolino <dom@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1281241}

--

wpt-commits: 38c6d6793e349f48b44950428bccd0f96d113b4e
wpt-pr: 45457

testing/web-platform/tests/dom/nodes/insertion-removing-steps/Node-appendChild-script-and-default-style-meta-from-fragment.tentative.html

@@ -7,29 +7,53 @@
 <div id="div">hello</div>
 <script>
 let scriptRan = false;
-let computedStyleDuringInsertion = null;
+let computedStyleInPreScript = null;
+let computedStyleInPostScript = null;
 test(() => {
  const div = document.getElementById("div");
+
+ // 1. Gets inserted *before* the `<meta>` tag. Cannot observe the meta tag's
+ // effect, because this script runs before the meta tag's post-insertion steps
+ // run, and the meta tag's post-insertion steps is where the default style
+ // sheet actually changes.
+ const preScript = document.createElement("script");
+ preScript.textContent = `
+ computedStyleInPreScript = getComputedStyle(div).display;
+ scriptRan = true;
+ `;
+
+ // 2. The `<meta>` tag itself.
  const meta = document.createElement("meta");
  meta.httpEquiv = "default-style";
  meta.content = "alternative";
- const script = document.createElement("script");
- script.textContent = `
- computedStyleDuringInsertion = getComputedStyle(div).display;
+
+ // 3. Gets inserted *after* the `<meta>` tag. Observes the meta tag's effect,
+ // because this script runs after the meta tag's post-insertion steps, which
+ // has the script-observable change to the default style sheet.
+ const postScript = document.createElement("script");
+ postScript.textContent = `
+ computedStyleInPostScript = getComputedStyle(div).display;
  scriptRan = true;
  `;
+
  const df = document.createDocumentFragment();
- df.appendChild(script);
- df.appendChild(meta);
- assert_equals(getComputedStyle(div).display, "block", "div has block display");
+ df.append(preScript, meta, postScript);
+
+ assert_equals(getComputedStyle(div).display, "block",
+ "div still has block display before meta insertion");
  assert_false(scriptRan, "script has not run before insertion");
+
  document.head.appendChild(df);
  assert_true(scriptRan, "script has run after insertion");
- assert_equals(computedStyleDuringInsertion, "none",
- "display: none; style was applied during DOM insertion, before " +
- "later-inserted script runs");
+ assert_equals(computedStyleInPreScript, "block",
+ "display: none; style was NOT applied during DOM insertion steps, " +
+ "before earlier-inserted script post-insertion steps run");
+ assert_equals(computedStyleInPostScript, "none",
+ "display: none; style WAS applied during DOM post-insertion steps, " +
+ "before later-inserted script runs");
  assert_equals(getComputedStyle(div).display, "none",
  "style remains display: none; after insertion");
+
 }, "Inserting <meta> that uses alternate stylesheets, applies the style " +
- "during DOM insertion, and before script runs as a result of any atomic insertions");
+ "during DOM post-insertion steps");
 </script>