Populate with function resolver

[alvaaz]

Hi everyone, I need help to pass function to populate some values. I'm using this function to populate.

export const category = async (categoryId: ObjectId): Promise<Category> => {
  try {
    const category = await CategoryModel.findById(categoryId)
    return {
      _id: category._id,
      name: category.name
    }
  } catch (err) {
    throw new Error(`Something goes wrong ${err}`)
  }
}

export const brand = async (brandId: ObjectId): Promise<Brand> => {
  try {
    const brand = await BrandModel.findById(brandId)
    return {
      _id: brand._id,
      name: brand.name
    }
  } catch (err) {
    throw new Error(`Something goes wrong ${err}`)
  }
}

I have 3 entities, Brands, Categories and Items.

The item entitiy look like this:

@ObjectType()
export class Item {
  @Field(() => Brand)
  @prop({ type: () => Brand })
  category: Brand

  @Field(() => Category)
  @prop({ type: () => Category })
  category: Category
}

export const ItemModel = getModelForClass(Item, { schemaOptions: { timestamps: true } })

and the resolver item is:

@Resolver(() => Item)
export default class ItemResolver {

  @Query(() => [Item])
  async items(): Promise<Item[] | undefined> {
    try {
      const items = await ItemModel.find()
      return items.map((item: Item) => {
        return {
          ....
          category: category(item.category),
          category: brand(item.brand)
          ....
        }
      })
    } catch (err) {
      throw new Error(`Something goes wrong ${err}`)
    }
  }
}

But, show me this error:

Type 'Promise<Category>' is not assignable to type 'Ref<Category>'.
  Type 'Promise<Category>' is missing the following properties from type 'Category': _id, name

How do I should to do it?