backend-and-orchestration-toolkit/code/protocol_demos/server-sent-events/index.js

/* Client Code 

let sse = new EventSource("http://localhost:8080/stream");
sse.onmessage = console.log

*/

const app = require("express")();

app.get("/", (req, res) => res.send("hello!"));

app.get("/stream", (req,res) => {

    res.setHeader("Content-Type", "text/event-stream");
    send(res);

})
const port = process.env.PORT || 8888;

let i = 0;
function send (res) {
    
    res.write("data: " + `hello from server ---- [${i++}]\n\n`);


    setTimeout(() => send(res), 1000);
}

app.listen(port)
console.log(`Listening on ${port}`)