testjade.js

var jade = require('jade')
  , mongoose =require('mongoose')
  , Schema = mongoose.Schema

var s = new Schema({ a: String });
s.virtual('asdf').get(function () {
  return 'i am a vritual'
});
var S = mongoose.model('S', s);

a = new S({ a: 'hi' });

fn = jade.compile('s = JSON.stringify(doc.toJSON({virtuals:true}))\nscript\n  var b = !{s}');
console.log(fn({ doc: a }))