[Solved] How to use virtual-dom's "h" helper in <head> for header-dropdown hamburger widget override? + How to override @computed method?

If you want to use the decorator syntax, you can do this

const computed = require("ember-addons/ember-computed-decorators").default;

Then you can do

api.modifyClass('component:edit-category-settings', {
    @computed("model.categoryId", "lastValidatedAt")
    availableSorts(categoryId, lastValidatedAt){
        let sorts = this._super();
        let voteSort = {};
        voteSort["name"] = "Votes";
        voteSort["value"] = "votes";
        sorts.push(voteSort);
        return sorts;
    }
  });

Notice that these lines are just a re-arranging of the import lines that you see in Discourse’s codebase. So anything you can import, you should be able to require in a theme.