<!DOCTYPE html> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <script src="/common/dispatcher/dispatcher.js"></script> <script src="/common/utils.js"></script> <script src="resources/utils.sub.js"></script> <script> promise_test(async t => { assert_implements(HTMLScriptElement.supports('speculationrules'), "Speculation Rules not supported"); let urls = Array(5).fill(getPrefetchUrlList(1)[0]); insertSpeculationRules({ prefetch: [{ source: 'list', urls: urls }] }); await new Promise(resolve => t.step_timeout(resolve, 2000)); let prefetched_count = (await Promise.all(urls.map(isUrlPrefetched))).reduce( (count, was_prefetched) => count + (was_prefetched ? 1 : 0), 0); assert_equals(prefetched_count, 1, "url should be prefetched just once."); }, "browser should remove duplicate urls from prefetch buffer."); </script>