将 Node Express 服务器上长时间运行的异步 function 的进度数据发送到反应客户端

Question

I want to be able to send some kind of progress data from a long running async function running on a node express server when a client requests for the data and waits for its completion.

const express = require('express');
const app = express();
const port = process.env.PORT;

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

    // Send data to client 
   (async () => {
      await someFunc();
   })();

})

Assuming someFunc() is responsible to return the progress data and the final response to the client.

Answer 1

Well, you can't do that since the first response will end the HTTP request (end the connection). What you looking for is WebSocket, with WebSocket you can keep pushing data to the client since it maintains the connection

check https://www.npmjs.com/package/websocket