Pulling data from Mongo DB not functioning as expected

I'm currently following the documentation on NestJS regarding the mongo db implementation. In the example they use a Cats database. Here I'm using a mongo db.

My schema is (categories.schema.ts):

export type CategoriesDocument = Categories & Document;

@Schema({ collection: 'categories' })

export class Categories {
  @Prop()
  id: number;

  @Prop()
  name: string;

  @Prop()
  slug: string;

  @Prop()
  created_at: Date;

  @Prop()
  updated_at: Date;
}

export const CategoriesSchema = SchemaFactory.createForClass(Categories);

I put this into my service in the constructor method:

import { Categories, CategoriesDocument } from './schema/categories.schema';

@Injectable()
export class CategoriesService {
  constructor(@InjectModel(Categories.name) private categoriesModel: Model<CategoriesDocument>) {}
...

In the same service I have:

  async findAll(): Promise<Categories> {
    return this.categoriesModel.find().exec();
  }

I then have a resolver (this is a graphql project) export class CategoriesResolver { constructor(private readonly categoriesService: CategoriesService) {} ...

  @Query(() => Category, { name: 'ocategory' })
  async ogetCategory(
    @Args('id', { type: () => ID }) id: number,
  ): Promise<Category> {
    return this.categoriesService.findAll();
  }

My Mongo collection looks like so:

_id
:
61bbd7dc86e25adaf8235981
id
:
8
name
:
"Nuts & Biscuits"
slug
:
"nuts-biscuits"
icon
:
null
image
:
Array
details
:
null
parent
:
Object
type_id
:
1
created_at
:
"2021-03-08T08:57:28.000000Z"
updated_at
:
"2021-03-08T08:57:28.000000Z"
deleted_at
:
null
parent_id
:
7
type
:
Object
children
:
Array

The error I get is:

src/categories/categories.service.ts:74:5 - error TS2739: Type '(Categories & Document<any, any, any> & { _id: any; })[]' is missing the following properties from type 'Categories': id, name, slug, created_at, updated_at

74     return this.categoriesModel.find().exec();
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Any idea what I'm doing wrong here?