Recently, I was testing the asynchronous behaviour of a nodejs express web application. My code was very simple
const express = require('express');
const app = express();
const port = 3000;
app.get('/', (req, res) => {
console.log(`hello main start`);
setTimeout(() => {
const date = new Date();
console.log(date);
res.send(`hello work done at ${date}!`);
}, 20000);
console.log(`hello main end`);
});
app.listen(port, () => {
console.log(`Example app listening on port ${port}`);
})
I found the experience that if I just open 2 tabs simultaneously to the endpoint url http://localhost:3000/ in my chrome browser without the developer tools opening, the request are fired one by one. How can I know they are are fired one by one is that when I observe the server console log, the second request only log start after when the request 1 finish. And hence I need 40 seconds to complete my 2 requests.
However I don't expect that above behaviour happens. So I try to do the same actions with postman.
But in this time, I found my postman will fire the 2 requests simultaneously and my server log the 2 request immediately as well.
What's more weird is that if I opens the 2 tab with chrome developer tool opening, the behaviour will be same as what I saw with the postman.
Can anyone have the explanation for this behaviour for the chrome? is it Google doing it on purpose on chrome?
