Monkey patch node's http client to print outgoing requests

outgoing-requests.js

const originalEnd = require('http').ClientRequest.prototype.end;
require('http').ClientRequest.prototype.end = function() {
  try {
    const headersSymbol = Object.getOwnPropertySymbols(this).find(k => k.toString().includes('kOutHeaders'))
    const host = this[headersSymbol]['host'][1];
    let protocol = this.agent && this.agent.protocol ? this.agent.protocol : 'unknown:'
    if (!this.agent && this[headersSymbol]['upgrade']) {
      protocol = 'ws:';
    }
    const url = `${protocol}//${host}${this.path}`;
    const method = this.method;
    console.log(`Outgoing request: ${JSON.stringify({
        url,
        method,
    })}`);
  } catch(ex) {
    console.log(`Failed to report request: ${ex}`)
  }
  return originalEnd.apply(this, arguments);
}

Ever wanted to inspect outgoing http requests from a node app?
We can simply monkey patch http client! 😉

For example, if you'd like to see what yarn is requesting, run (after saving the script above as inspect-outgoing-http.js):

NODE_OPTIONS="--require=./inspect-outgoing-http" yarn