How to fix EventSource onmessage not working in JavaScript All in One

SSE: Server-Sent Events / 服务端推送

error ❌

window.addEventListener(`load`, (e) => {
  console.log(`page loaded ✅`);
  if (!!window.EventSource) {
    const img = document.querySelector(`#sse`);
    const source = new EventSource('http://localhost:3000/sse');
    source.onopen = (event) => {
      console.log(`✅ Connection to server opened.`, event);
    };
    source.onmessage = (event) => {
      const data = event.data;
      console.log(`

标签：const,log,working,res,fix,JavaScript,console,data,event	

From： https://www.cnblogs.com/xgqfrms/p/17783689.html