test(history): snapshot child traversal events after completion

moli-core/tests/fixtures/runtime/window_child_browsing_context_fragment_traversal_events_are_window_local.html

@@ -17,6 +17,7 @@
         document.body.setAttribute('data-done', '1');
 
         const childWindow = iframe.contentWindow;
+        let finishTraversal;
 
         childWindow.addEventListener('popstate', () => {
           childOrder.push('child-popstate');
@@ -29,6 +30,7 @@
           document.body.setAttribute('data-child-new', event.newURL);
           queueMicrotask(() => {
             childOrder.push('child-hashchange-microtask');
+            finishTraversal?.();
           });
         });
 
@@ -41,14 +43,19 @@
           document.body.removeAttribute('data-child-old');
           document.body.removeAttribute('data-child-new');
 
+          const traversalCompleted = new Promise(resolve => {
+            finishTraversal = resolve;
+          });
           childWindow.history.back();
           document.body.setAttribute('data-child-sync-hash', childWindow.location.hash);
 
-          setTimeout(() => {
-            document.body.setAttribute('data-top-order', topOrder.join(','));
-            document.body.setAttribute('data-child-order', childOrder.join(','));
-            document.body.setAttribute('data-child-timeout-hash', childWindow.location.hash);
-          }, 50);
+          traversalCompleted.then(() => {
+            setTimeout(() => {
+              document.body.setAttribute('data-top-order', topOrder.join(','));
+              document.body.setAttribute('data-child-order', childOrder.join(','));
+              document.body.setAttribute('data-child-timeout-hash', childWindow.location.hash);
+            }, 50);
+          });
         }, 50);
       });
     </script>

moli-core/tests/history_child.rs

@@ -4073,9 +4073,7 @@ async fn child_browsing_context_fragment_traversal_events_stay_window_local() ->
             "/compat/window-child-browsing-context-fragment-traversal-events-are-window-local",
         ))
         .await?;
-    browser
-        .wait_for_page_delay(&mut page, Duration::from_millis(250))
-        .await?;
+    wait_for_body_attribute(&browser, &mut page, "data-child-timeout-hash", "#one").await?;
 
     assert!(
         page.serialize_html_async()