index.js

var byline = require('byline');
var stream = require('stream');

function MyTransform1() {
  stream.Transform.apply(this, arguments);
}
MyTransform1.prototype = stream.Transform.prototype;
MyTransform1.prototype._transform = function(chunk, encoding, done) {
  this.push(chunk.toString().toUpperCase());
  done();
};

function MyTransform2() {
  stream.Transform.apply(this, arguments);
}
MyTransform2.prototype = stream.Transform.prototype;
MyTransform2.prototype._transform = function(chunk, encoding, done) {
  this.push(chunk + ' foo');
  done();
};

// this should produce upper-case lines w/ lower-case "foo" at the end, but the
// lines aren't uppercase
process.stdin
  .pipe(byline.createStream())
  .pipe(new MyTransform1())
  .pipe(new MyTransform2())
  .pipe(process.stdout);