Accumulating files in memory

[Pooyahmti]

Running below code, with evey request, the app memory usage ( RSS ) increases until server runs out of memory. Why the buffers are not garbage collected after response is sent ?

import http from 'http'
import busboy from 'busboy'

http.createServer((req, res) => {

  if (req.method === 'POST') {
    const bb = busboy({ headers: req.headers });
    bb.on('file', (name, file, info) => {
      const chunks = [];
      file.on('data', (data) => {
        chunks.push(data);
      })
      file.on('end', () => {
        console.log(info, Buffer.concat(chunks));
      })
    })
    bb.on('close', () => {
      res.writeHead(200, { Connection: 'close' });
      res.end("Data Received")
    });
    req.pipe(bb);
  }
}).listen(3000, () => {
  console.log("Listening for requests")
})