gulp. Why is session data lost when building javascript?

Question

Node.js

Hello, I'm having a problem understanding how gulp and node.js work. Can you please explain why I am losing session data?
I run gulp watch (or just gulp js).
I'm editing some javascript.
I save (task 'js' is running)
I reload the page and see that the session is gone...?
This does not happen when building css or images.
Link to weight gulpfile.js https://gist.github.com/batazor/15bb05856f298da122fe
And specifically task js

gulp.task('js', function() {
  return gulp.src(watch.js)
    .pipe(concat('index.js'))
    .on('error', console.log)
    .pipe(uglify())
    .pipe(gulp.dest(public.js))
    .pipe(notify({ message: 'JS task complete' }));
});

PS I write on Node.js (express) For sessions I use passport

Answer 1

For the changes to JS to take effect, you need to restart the Node.js process. If your sessions are not stored in external storage (memcached, redis, mongo) and not in cookies, but in the process memory, then they will naturally die upon restart. Which is most likely what is happening in your case.