Why does express return an empty req.body?

Question

Node.js

Please tell me, I raised the server locally / I
use express "^4.17.2"

const express = require('express');
const { v4: uuidv4 } = require('uuid');
const app = express();
const port = 3000;

app.use(express.urlencoded({ extended: false }))
app.use(express.json());

app.post('/api/text', (req, res) => {
  console.log("---", req.body);
  res.send("text");

})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`)
})

I send a POST request via postman, req.body is always an empty object

Please tell me what I'm doing wrong?

Answer 1

Express ^4x comes without body-parser, you need to include it separately

Answer 2

Option N1
Connect body-parser

The code

npm install body-parser

const express = require('express');
const { v4: uuidv4 } = require('uuid');
const app = express();
const port = 3000;
const bodyParser = require('body-parser');

app.use(express.urlencoded({ extended: false }))
app.use(express.json());

app.use(bodyParser.json())

app.post('/api/text',(req, res) => {
    console.log("---", req.body);
    res.send("text");

})

app.listen(port, () => {
    console.log(`Example app listening on port ${port}`)
})

Option N2
Using chunk.
IMPORTANT. Do the output inside end or remake the code into an asynchronous function and do await for on('data'). In this case, body can only be called inside:

req.on('end', () => {
        console.log("---", body);
    });

otherwise, it will be empty, because body does not have time to write, and on.('end') is executed.

The code

const express = require('express');
const { v4: uuidv4 } = require('uuid');
const app = express();
const port = 3000;

app.use(express.urlencoded({ extended: false }))
app.use(express.json());

app.post('/api/text',(req, res) => {
    let body = '';
    req.on('data', chunk => {
        body += chunk.toString();
    });
    req.on('end', () => {
        console.log("---", body);
    });
    res.send("text");

})

app.listen(port, () => {
    console.log(`Example app listening on port ${port}`)
})