Hi,

in the file testprep.js, I tried the following variations:

// #define var DEBUG=1
(or)
// #define DEBUG 1
(or)
// #define DEBUG=1

(and then in the same file):
// #ifdef DEBUG
console.log('debug');
// #else
console.log('nodebug');
// #endif

console.log('after');

However, the output is always the same:
$ preprocess testprep.js

console.log('nodebug');

console.log('after');

So either I'm completely misinterpreting the intent, or it isn't working