Describe the bug

I observe a potential memory leak while posting data from a stream using Axios.

To Reproduce

Having a fake server (nc -kl localhost 5000), let's profile this simple script:

mprof run -C -T1 timeout 60 node test_axios.js < /dev/urandom

// test_axios.js
const axios = require("axios");
const followRedirects = require("follow-redirects");
followRedirects.maxBodyLength = Number.MAX_SAFE_INTEGER;
axios.post("http://localhost:5000", process.stdin);

This produces the following chart:

Expected behavior

Then consider the following equivalent axios-agnostic script:

const http = require("http");
const options = {
  host: "localhost",
  port: "5000",
  path: "/",
  method: "POST"
};
const req = http.request(options, res => {});
process.stdin.pipe(req);

It produces:

Here the memory is properly garbaged.

Environment:

• Axios Version [e.g. 0.19.2]
• OS: Ubuntu 18.04.4
• Profiling tool: memory-profiler