1 files changed, 22 insertions, 0 deletions
diff --git a/testing/web-platform/tests/preload/resources/prefetch-helper.js b/testing/web-platform/tests/preload/resources/prefetch-helper.js
new file mode 100644
index 0000000000..367d4824c4
--- /dev/null
+++ b/testing/web-platform/tests/preload/resources/prefetch-helper.js
@@ -0,0 +1,22 @@
+async function get_prefetch_info(href) {
+    const response = await fetch(`${href}&mode=info`, {mode: "cors"});
+    return await response.json();
+}
+
+async function prefetch(p = {}, t) {
+    const link = document.createElement("link");
+    link.rel = "prefetch";
+    link.as = p.as;
+    if (p.crossOrigin)
+        link.setAttribute("crossorigin", p.crossOrigin);
+    const uid = token();
+    const params = new URLSearchParams();
+    params.set("key", uid);
+    for (const key in p)
+        params.set(key, p[key]);
+    const origin = p.origin || '';
+    link.href = `${origin}/preload/resources/prefetch-info.py?${params.toString()}`;
+    document.head.appendChild(link);
+    while (!(await get_prefetch_info(link.href)).length) { }
+    return {href: link.href, uid};
+}