Big bug for vendure handle typeorm for custom fields with `relation` & `eager:true`

[tianyingchun]

Describe the bug If we use customFields with using relation with eager:true for productVariant and we have any other service like below

return this.listQueryBuilder
      .build(SupplierStockInTransit, options, {
        ctx,
        relations: ['supplierStock', 'supplierStock.productVariant'],
 })

To Reproduce

Please the minimal repo https://github.com/tianyingchun/vendure-issue

Installation

• yarn install
• yarn serve

Preparing sample data maybe not required for this case

http://localhost:3001/admin-api

mutation {
  initializeDemo
}

Issue reproduce steps

http://localhost:3001/admin-api

{
  supplierStockInTransits(options: { skip: 0, take: 100 }) {
    items {
      id
      supplierStock {
        id
        productVariant {
          id
        }
      }
    }
  }
}

See errors

[ExceptionsHandler] Not unique table/alias: 'SuStInTr__suSt__prVaFiFrAs'
@semic/dev-server: QueryFailedError: Not unique table/alias: 'SuStInTr__suSt__prVaFiFrAs'
@semic/dev-server:     at QueryFailedError.TypeORMError [as constructor]

Analysis of above problems

1. /custom-fields/product-variant-custom-fields.ts custom fields definitions as below with eager: true

{
    type: 'relation',
    name: 'tryonFrameAsset',
    nullable: true,
    entity: Asset,
    eager: true,
    public: true,
  },
  {
    type: 'relation',
    name: 'tryonTempleAsset',
    nullable: true,
    entity: Asset,
    eager: true,
    public: true,
  },
  ...

2. In supplier-stock-in-transit.service.ts we attach nested relations supplierStock.productVariant

  findAll(
    ctx: RequestContext,
    options?: ListQueryOptions<SupplierStockInTransit>
  ): Promise<PaginatedList<SupplierStockInTransit>> {
    return this.listQueryBuilder
      .build(SupplierStockInTransit, options, {
        ctx,
        relations: ['supplierStock', 'supplierStock.productVariant'],
      })
      .getManyAndCount()
      .then(([items, totalItems]) => {
        return {
          items,
          totalItems,
        };
      });
  }

This issue may cause of custom Fields with nested relation with eager: true

Environment (please complete the following information):

• @vendure/core version:1.8.3
• Nodejs version: 18
• Database (mysql/postgres etc):mysql

Additional context Add any other context about the problem here.

[michaelbromley]

Thanks for putting in the work of creating a full reproduction! That's very, very helpful to me 👍

Initial investigation looks like it may have something to do with

• https://github.com/typeorm/typeorm/issues/2661

and could be related to the naming strategy for shortening aliases - when shortening the alias, entity names are getting truncated any maybe this is leading to naming clashes.

[michaelbromley]

So I'm pretty sure I have tracked down the root cause:

There is this shorten function which is invoked if the alias name is greater than 63 chars long. The shortening algorithm it uses is creating identical aliases for multiple of the eager-loaded custom field relations. See the linked issue I just created in the TypeORM repo.

So a work-around for now is to rename your custom fields in a way that does not cause a conflict after shortening.