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Test Info:
- Manifest: netwerk/test/mochitests/mochitest.toml
<!DOCTYPE HTML>
<html>
<!--
-->
<head>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<p id="display"></p>
<pre id="test">
<script type="application/javascript">
SimpleTest.waitForExplicitFinish();
const SJS_PATH = "/tests/netwerk/test/mochitests/prefetch_cache.sjs";
function getRequestCount(key) {
return fetch(`${SJS_PATH}?key=${key}&mode=count`)
.then(r => r.text())
.then(t => parseInt(t));
}
function resetCount(key) {
return fetch(`${SJS_PATH}?key=${key}&mode=reset`);
}
function prefetchAndWait(url) {
return new Promise((resolve, reject) => {
const link = document.createElement("link");
link.rel = "prefetch";
link.href = url;
link.addEventListener("load", () => resolve(link));
link.addEventListener("error", () => reject(new Error("prefetch failed")));
document.head.appendChild(link);
});
}
function loadScript(url) {
return new Promise((resolve, reject) => {
const script = document.createElement("script");
script.src = url;
script.addEventListener("load", () => {
script.remove();
resolve();
});
script.addEventListener("error", () => {
script.remove();
reject(new Error("script load failed"));
});
document.body.appendChild(script);
});
}
// ForceCacheEntryValidFor should be called, so a subsequent load
// reuses the prefetched cache entry instead of re-fetching.
async function testPrefetchCacheNoHeaders() {
const key = "no-headers-" + Date.now();
const url = `${SJS_PATH}?key=${key}&type=application/javascript`;
await resetCount(key);
const link = await prefetchAndWait(url);
let count = await getRequestCount(key);
is(count, 1, "No cache headers: prefetch made exactly one request");
await loadScript(url);
count = await getRequestCount(key);
is(count, 1,
"No cache headers: second load reused prefetched cache entry");
link.remove();
}
// Prefetch a resource with max-age=3600.
// ForceCacheEntryValidFor should NOT be called because the response
// already has cache headers. The normal cache mechanism handles reuse.
async function testPrefetchCacheWithMaxAge() {
const key = "max-age-" + Date.now();
const url = `${SJS_PATH}?key=${key}&type=application/javascript&cache-control=max-age%3D3600`;
await resetCount(key);
const link = await prefetchAndWait(url);
let count = await getRequestCount(key);
is(count, 1, "max-age=3600: prefetch made exactly one request");
await loadScript(url);
count = await getRequestCount(key);
is(count, 1,
"max-age=3600: second load reused cache entry via normal caching");
link.remove();
}
// Prefetch a resource with no-store.
// nsPrefetchService cancels the prefetch in OnStartRequest because no-store
// has MustValidate = true, giving expTime = 0. The HTTP request is still sent
// so the server count reaches 1, but the body is not downloaded and the cache
// entry is doomed. The prefetch fires an error event rather than load.
async function testPrefetchCacheNoStore() {
const key = "no-store-" + Date.now();
const url = `${SJS_PATH}?key=${key}&type=application/javascript&cache-control=no-store`;
await resetCount(key);
const link = await new Promise((resolve) => {
const l = document.createElement("link");
l.rel = "prefetch";
l.href = url;
l.addEventListener("load", () => resolve(l));
l.addEventListener("error", () => resolve(l));
document.head.appendChild(l);
});
let count = await getRequestCount(key);
is(count, 1, "no-store: prefetch made exactly one request");
await loadScript(url);
count = await getRequestCount(key);
is(count, 2,
"no-store: second load correctly re-fetched from server");
link.remove();
}
// Prefetch a resource with max-age=0 (immediately expired).
// nsPrefetchService cancels the prefetch in OnStartRequest to avoid wasting
// bandwidth on a response that must be revalidated. The HTTP request is still
// sent so the server count reaches 1, but the body is not downloaded and the
// cache entry is doomed, so the subsequent load re-fetches from the server.
// Because the prefetch is cancelled, the link fires an error event, not load.
async function testPrefetchCacheExpiredWithHeaders() {
const key = "max-age-0-" + Date.now();
const url = `${SJS_PATH}?key=${key}&type=application/javascript&cache-control=max-age%3D0`;
await resetCount(key);
const link = await new Promise((resolve) => {
const l = document.createElement("link");
l.rel = "prefetch";
l.href = url;
l.addEventListener("load", () => resolve(l));
l.addEventListener("error", () => resolve(l));
document.head.appendChild(l);
});
let count = await getRequestCount(key);
is(count, 1, "max-age=0: prefetch made exactly one request");
await loadScript(url);
count = await getRequestCount(key);
is(count, 2,
"max-age=0: second load re-fetched because server cache directive was respected");
link.remove();
}
async function runTests() {
await SpecialPowers.pushPrefEnv({
set: [
["network.prefetch-next", true],
["network.prefetch-next.force-valid-for", 300],
],
});
await testPrefetchCacheNoHeaders();
await testPrefetchCacheWithMaxAge();
await testPrefetchCacheNoStore();
await testPrefetchCacheExpiredWithHeaders();
SimpleTest.finish();
}
runTests();
</script>
</pre>
</body>
</html>