1 files changed, 15 insertions, 0 deletions
diff --git a/dom/serviceworkers/test/fetch/imagecache/imagecache_test.js b/dom/serviceworkers/test/fetch/imagecache/imagecache_test.js
new file mode 100644
index 0000000000..e1f2af736b
--- /dev/null
+++ b/dom/serviceworkers/test/fetch/imagecache/imagecache_test.js
@@ -0,0 +1,15 @@
+function synthesizeImage() {
+  return clients.matchAll().then(clients => {
+    var url = "image-40px.png";
+    clients.forEach(client => {
+      client.postMessage(url);
+    });
+    return fetch(url);
+  });
+}
+
+self.addEventListener("fetch", function(event) {
+  if (event.request.url.includes("image-20px.png")) {
+    event.respondWith(synthesizeImage());
+  }
+});