Resolve one to many relation Nest.js / GraphQL Federation with Mercurius - graphql

Question

I am using Nest.js / GraphQL Federation with Mercurius. I have two entities Products and Store that reside in different apps. The store should have multiple products as one to many relationship. I have a StoresQueries resolver that has a method findAll that returns a StoresPagination object. Each returned store object does not have the fields mentioned in the products app from the apps/products/src/products/resolvers/Store.resolver.ts and same apps/products/src/products/models/Store.model.ts I want to keep stuff decoupled and more or less the same structure works fine on other entities.
Project structure
apps/
store/
src/
store/
models/
Store.model.ts
resolvers/
Store.resolver.ts
StoresQueries.resolver.ts
services/
Store.service.ts
Store.module.ts
App.module.ts
main.ts
products/
src/
store/
models/
Store.model.ts
Product.model.ts
resolvers/
Store.resolver.ts
Product.resolver.ts
services/
Product.service.ts
Product.module.ts
App.module.ts
main.ts
apps/store/src/models/Store.model.ts
#ObjectType()
#Directive('#key(fields: "id")')
export class Store {
#Field(() => ID)
id: string;
#Field()
#TextSearch()
name: string;
}
apps/store/src/resolvers/Store.resolver.ts
#Resolver(() => Store)
export class StoreResolver {
constructor(private readonly storeService: StoreService) {}
#Query(() => StoresQueries, { name: 'stores' })
async storesQueries(): Promise<StoresQueries> {
return {};
}
#ResolveReference()
async resolveReference(reference: {
__typename: string;
id: string;
}): Promise<Store> {
return this.storeService.findById(reference.id);
}
}
apps/store/src/resolvers/StoresQueries.resolver.ts
#Resolver(() => StoresQueries)
export class StoresQueriesResolver {
constructor(private storeService: StoreService) {}
#ResolveField(() => StorePagination)
async findAll(
#CurrentUser() user: JwtUser,
#Args('input', { nullable: true }) input: PaginationInput | null,
): Promise<StorePagination> {
return this.storeService.findAll(input?.cursor, input?.limit);
}
}
app/products/src/products/models/Store.model.ts
#ObjectType()
#Directive('#key(fields: "id")')
#Directive('#extends')
export class Store {
#Directive('#external')
#Field(() => ID)
id: string;
// these both fields are not shown when querying StoresQueries for each store
#Field(() => ProductsPagination, { nullable: true })
products?: ProductsPagination;
#Field(() => Number, { nullable: true })
dummyCount?: number;
}
app/products/src/products/models/Product.model.ts
#ObjectType()
#Directive('#key(fields: "id")')
#Label('product', ['id'])
export class Product {
#Field(() => ID)
id: string;
}
app/products/src/products/resolvers/Product.resolver.ts
#Resolver(() => Product)
export class ProductsResolver {
constructor(
private productsService: ProductsService,
) {}
#ResolveReference()
async resolveReference(reference: {
__typename: string;
id: string;
}): Promise<Product> {
return this.productsService.findById(reference.id);
}
}
app/products/src/products/resolvers/Store.resolver.ts
#Resolver(() => Store)
export class StoreResolver {
constructor(
private productsService: ProductsService,
) {}
#ResolveField(() => ProductsPagination, { nullable: true })
async products(
#Parent() parent: Store,
#Args('input', { nullable: true }) input: PaginationInput | null,
): Promise<ProductsPagination> {
const wp = this.productsService.getProductsByStoreId(
parent.id,
kind,
input,
);
return { __typename: 'ProductsPagination', ...wp };
}
}