1 files changed, 3 insertions, 0 deletions
diff --git a/testing/web-platform/tests/service-workers/service-worker/resources/postmessage-echo-worker.js b/testing/web-platform/tests/service-workers/service-worker/resources/postmessage-echo-worker.js
new file mode 100644
index 0000000000..f088ad1278
--- /dev/null
+++ b/testing/web-platform/tests/service-workers/service-worker/resources/postmessage-echo-worker.js
@@ -0,0 +1,3 @@
+self.addEventListener('message', event => {
+  event.source.postMessage(event.data);
+});