1 files changed, 26 insertions, 0 deletions
diff --git a/testing/web-platform/tests/custom-elements/form-associated/ElementInternals-target-element-is-held-strongly.html b/testing/web-platform/tests/custom-elements/form-associated/ElementInternals-target-element-is-held-strongly.html
new file mode 100644
index 0000000000..a747c04c5c
--- /dev/null
+++ b/testing/web-platform/tests/custom-elements/form-associated/ElementInternals-target-element-is-held-strongly.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<title>Target element of ElementsInternals is held strongly and doesn't get GCed if there are no other references</title>
+<body>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/gc.js"></script>
+
+<script>
+customElements.define("x-foo", class extends HTMLElement {});
+
+promise_test(async t => {
+    const elementInternals = [];
+
+    for (let i = 0; i < 1e5; i++) {
+        const targetElement = document.createElement("x-foo");
+        targetElement.attachShadow({ mode: "open" });
+        elementInternals.push(targetElement.attachInternals());
+    }
+
+    await garbageCollect();
+    await new Promise(r => t.step_timeout(r, 100));
+
+    const allShadowRootsAreAlive = elementInternals.every(eI => eI.shadowRoot instanceof ShadowRoot);
+    assert_true(allShadowRootsAreAlive);
+});
+</script>