Defining eager: true on customField stops custom entity to load own eager relations

[tschortsch]

Describe the bug
I've created a custom entity Cut which looks like the following:

@Entity()
export class Cut extends VendureEntity {
    constructor(input?: DeepPartial<Cut>) {
        super(input);
    }

    @ManyToOne(() => OrderLine, { onDelete: 'CASCADE' })
    orderLine: OrderLine;

    @EntityId()
    orderLineId: ID;

    // code field needs to be loaded eagerly to be able to access its subfields in vendure queries
    @ManyToOne(() => CutCode, { eager: true })
    code: CutCode;

    @EntityId()
    codeId: ID;
}

On the OrderLine I created a customField called cuts which is a ManyToMany relation to the Cut entity above:

config.customFields.OrderLine.push({
    name: 'cuts',
    type: 'relation',
    entity: Cut,
    list: true,
    eager: true,
    label: [
        {
            languageCode: LanguageCode.en,
            value: 'Cuts',
        },
    ],
});

I had to set eager: true because otherwise the addItemToOrder mutation would ignore the customField.cuts when checking if an orderLine already exists for the given productVariant with OrderModifier.getExistingOrderLine() (here: https://github.com/vendure-ecommerce/vendure/blob/master/packages/core/src/service/helpers/order-modifier/order-modifier.ts#L131). This is because the cuts relations is not resolved in the order without loading the relation eagerly.

But as soon as I define this customField to be resolved eagerly all subrelations of this entity (in this case the code field) are not loaded eagerly anymore. I guess this happens because of this logic here: https://github.com/vendure-ecommerce/vendure/blob/master/packages/core/src/api/config/generate-resolvers.ts#L214 which directly returns the translated entity instead of resolving the relation again. It was introduced in this change tianyingchun@3211d75 which fixes the translation of the entity. When I skip the line above locally the code-relation of the Cut entity is resolved eagerly again.

Environment (please complete the following information):

• @vendure/core version: 2.1.4
• Nodejs version: 18
• Database (mysql/postgres etc): postgres

[michaelbromley]

Hi,

Thanks for the report. Would you be able to create a minimal reproduction I could use to quickly investigate this?

Ideally something like a single-file plugin I can paste into my own config file, plus queries/mutations I can copy-paste that clearly demonstrate the problem.

If you have time to do that it will really help me rapidly find a fix :)

[tschortsch]

Sure makes sense. I try to do that as fast as possible. Thanks for your help 👍🏻

[tschortsch]

Ok I could create a minimal reproduction plugin. You'll find it here: https://gist.github.com/tschortsch/5e11413dda42f6df0a7106834306c05d#file-eager-relations-bug-plugin-ts. To reproduce the bug you have to do the following:

1. Setup a vendure instance

2. The instance needs to have a product variant with the ID: 1 (Or change the hardcoded productVariantId in the plugin to an existing product variant id)

3. Create a new migration for the custom field and the entities and run it.

4. Start vendure and execute the following mutation in the shop-api:

   mutation AddCutToOrder {
     addCutToOrder {
       id
       lines {
         id
         customFields {
           cuts {
             id
             name
             code {
               id
               code
             }
           }
         }
       }
     }
   }
   

This will create an Order with an OrderLine and adds a Cut with a related CutCode to this OrderLine. When trying to access the code property in the response it will throw the following error Cannot return null for non-nullable field Cut.code..
As soon as you set the customField.cuts relation to eager: false it will work again.

Hope this helps!

[michaelbromley]

Thanks for supplying the reproduction gist. Note that I had to change these lines to get the mutation to work to:

        if (!orderLine) {
            const result = await this.orderService.addItemToOrder(ctx, sessionOrder.id, 1, 1);
            if (isGraphQlErrorResult(result)) {
                throw result.message;
            } else {
                orderLine = result.lines[result.lines.length - 1];
            }
        }

This looks like a potential TypeORM bug. What I'm going to do is leave this for now and test it with the upcoming v2.2 in which we have made a major upgrade to TypeORM from v0.3.11 to v0.3.20. If the issue still remains there I'll dive deeper.

[michaelbromley]

An issue was fixed in v2.2.1 that may resolve this (see commit referenced above)

[tschortsch]

Upgraded to v2.2.2 but the eager relation is still not resolved when the customField relation is set to eager: true 😏