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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /fetch/api/request/request-stream-service-worker.h2.html - WPT Dashboard Interop Dashboard
<!doctype html>
<meta charset="utf-8">
<title>Service worker upload backpressure</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/service-workers/service-worker/resources/test-helpers.sub.js"></script>
<script>
async function setupWorker(t) {
const controlled = new Promise(resolve => {
navigator.serviceWorker.addEventListener("controllerchange", resolve, { once: true });
});
const registration = await service_worker_unregister_and_register(
t, "request-stream-service-worker.js", location.pathname);
t.add_cleanup(() => registration.unregister());
await wait_for_state(t, registration.installing, "activated");
await controlled;
const channel = new MessageChannel();
t.add_cleanup(() => channel.port1.close());
const connected = new Promise(resolve => channel.port1.onmessage = resolve);
registration.active.postMessage(null, [channel.port2]);
await connected;
return channel.port1;
}
// The worker holds the intercepted upload without reading it, so the page's
// producer must stall on the transfer's capacity rather than be drained.
promise_test(async t => {
const port = await setupWorker(t);
const ready = new Promise(resolve => port.onmessage = resolve);
const abort = new AbortController();
t.add_cleanup(() => abort.abort());
let cancel;
const cancelled = new Promise(resolve => cancel = resolve);
let pulls = 0;
const response = fetch("sw-upload-backpressure", {
method: "POST",
duplex: "half",
signal: abort.signal,
body: new ReadableStream({
pull(controller) {
controller.enqueue(new Uint8Array(65536));
if (++pulls === 256) {
controller.close();
}
},
cancel,
}, { highWaterMark: 0 }),
});
await ready;
// A body buffered for replay would have taken all 16MB by now.
await new Promise(resolve => t.step_timeout(resolve, 100));
assert_less_than(pulls, 256, "An unread SW upload must not drain the producer");
port.postMessage("cancel");
assert_equals(await (await response).text(), "cancelled");
await cancelled;
}, "An unread service-worker upload preserves backpressure and propagates cancellation");
// An unhandled fetch event returns the worker's unread body to the channel, so
// the server still sees it and the worker's own body ends closed and disturbed.
promise_test(async t => {
const port = await setupWorker(t);
const observed = new Promise(resolve => port.onmessage = event => resolve(event.data));
const response = await fetch("/fetch/api/resources/echo-content.h2.py?sw-upload-fallback", {
method: "POST",
duplex: "half",
body: new ReadableStream({
start(controller) {
controller.enqueue(new TextEncoder().encode("fallback body"));
controller.close();
},
}),
});
assert_equals(await response.text(), "fallback body");
const state = await observed;
assert_true(state.bodyUsed);
assert_false(state.locked);
assert_true(state.done);
}, "Network fallback closes and disturbs the worker body without locking it");
</script>