ServiceWorkerContainer: message

addEventListener("message", (event) => {});

onmessage = (event) => {};

// 
async function messageClient(clientId) {
  const client = await clients.get(clientId);
  client.postMessage("");
}

addEventListener("fetch", (event) => {
  messageClient(event.clientId);
  event.respondWith(() => {
    // 
  });
});

// main.js
navigator.serviceWorker.addEventListener("message", (message) => {
  console.log(message);
});

// main.js
navigator.serviceWorker.onmessage = (message) => {
  console.log(message);
};