How to subscribe to rawCollection?

I have “Categories” collection on the server and the client,
I have this pub on the server:

Meteor.publish('categories', function() {
    return Categories.rawCollection().distinct('category');

and I have this sub on the client:

let categories = Categories.find()

I think it should work, but it doesn’t.
so what is wrong with this code?

The issue here is that the rawCollection methods are not wrapped with Futures into synchronous style. What you need to do is something like:

const raw = Categories.rawCollection();
const distinct = Meteor.wrapAsync(raw.distinct, raw);

Meteor.publish('categories', function() {
    return distinct('category');