var duo = require('gulp-duojs');

gulp.task('dest.js', function () {
  gulp.src('src/index.js')
    .pipe(duo({standalone: 'foobar'}))
    .pipe(gulp.dest('./dest'));
});

var duo = require('gulp-duojs');

gulp.task('dest.js', function () {
  gulp.src('src/index.js')
    .pipe(duo({standalone: 'foobar'}, function (Duo) {
        Duo.include('jade-runtime', ...);
    }))
    .pipe(gulp.dest('./dest'));
});