bodyParser ignores maxBodySize and buffers whole file in memory for file uploads

The bodyParser middleware seems to buffer the whole file in memory for file uploads.

Check the following minimum example:

'use strict';

var os = require( 'os' );
var restify = require( 'restify' );

var server = restify.createServer( {} );

server.use( restify.bodyParser( {
  // this should supposedly limit maximum upload size to 10 KiB
  maxBodySize: 10 * 1024,
  mapParms: true,
  mapFiles: true,
  keepExtensions: true,
  uploadDir: os.tmpdir()
} ) );

server.get( '/', function( req, res, next ) {
  res.json( { message: 'hello' } );
  next();
} );

server.post( '/upload', function( req, res, next ) {
  console.log( 'Received files:', req.files );
  res.send( 200 );
  next();
} );

server.listen( 8000 );

Then, upload a really big file to it:

# bigfile.dat has a couple of GiB
curl -F "file=@/path/to/bigfile.dat" localhost:8000/upload

This will send the process into accumulating tons of memory until it eventually runs out of memory and crashes with:

FATAL ERROR: JS Allocation failed - process out of memory

Am I making a mistake in setting up the middleware or is this a bug?

Reproduce the upload with the provided bodyParser configuration and a large file, then trace restify.bodyParser through the repository to find where maxBodySize is applied. Check how file uploads are buffered and run the relevant existing tests, if present. Done means uploads over the limit are rejected without buffering the entire file or exhausting process memory.