1 files changed, 32 insertions, 0 deletions
diff --git a/dom/tests/mochitest/fetch/nested_worker_wrapper.js b/dom/tests/mochitest/fetch/nested_worker_wrapper.js
new file mode 100644
index 0000000000..1a14cf06d9
--- /dev/null
+++ b/dom/tests/mochitest/fetch/nested_worker_wrapper.js
@@ -0,0 +1,32 @@
+function getScriptUrl() {
+  return new URL(location.href).searchParams.get("script");
+}
+
+// Hold the nested worker alive until this parent worker closes.
+var worker;
+
+addEventListener("message", function nestedWorkerWrapperOnMessage(evt) {
+  removeEventListener("message", nestedWorkerWrapperOnMessage);
+
+  worker = new Worker("worker_wrapper.js?script=" + getScriptUrl());
+
+  worker.addEventListener("message", function (evt) {
+    self.postMessage({
+      context: "NestedWorker",
+      type: evt.data.type,
+      status: evt.data.status,
+      msg: evt.data.msg,
+    });
+  });
+
+  worker.addEventListener("error", function (evt) {
+    self.postMessage({
+      context: "NestedWorker",
+      type: "status",
+      status: false,
+      msg: "Nested worker error: " + evt.message,
+    });
+  });
+
+  worker.postMessage(evt.data);
+});