1let promise_func = null; 2let promise = new Promise(resolve => promise_func = resolve); 3 4const SERVICE_WORKER_TEST_CHANNEL_NAME = 'service worker'; 5const bc3 = new BroadcastChannel(SERVICE_WORKER_TEST_CHANNEL_NAME); 6bc3.onmessage = e => { 7 bc3.postMessage('done'); 8 promise_func(); 9}; 10bc3.postMessage('from worker'); 11 12// Ensure that the worker stays alive for the duration of the test 13self.addEventListener('install', evt => { 14 evt.waitUntil(promise); 15}); 16