The HTTP TRACE method is a valuable tool for conducting a message loop-back test along the path to the target resource, making it an essential debugging mechanism. The final recipient of the request must echo back the received message as the body of a 200 (OK) response with a Content-Type of message/http.
Here's an illustration of an HTTP request using the TRACE method:
https://i.stack.imgur.com/7nxQu.jpg
And here's an example of a response to a request made with the TRACE method:
https://i.stack.imgur.com/rxw1a.jpg
const path = require( 'path' );
const express = require( 'express' ); // version 4.x
const favicon = require( 'serve-favicon' );
const app = express();
app .use( favicon( path.join( __dirname, 'assets', 'logo.ico' ) ) );
app.trace( '*', ( req, res ) => {
// How can I send the entire original request back in the response?
} );