Prisma Read Replica plugin create errors on the Graphql types

[alacret]

Hi community, for some reasons that I don't understand, using the plugin for Read Replicas breaks the autogenerated types.

In a very simple use case, when generating the prisma client for the GraphQL context:

going from:

  const prismaConnection = new PrismaClient({
    datasources: {
      db: {
        url: writeUrl,
      },
    },
  });

to:

  const prismaConnection = new PrismaClient({
    datasources: {
      db: {
        url: writeUrl,
      },
    },
  }).$extends(
    readReplicas({
      url: readUrls,
    }),
  ) as unknown as PrismaClient;

This starts creating errors in the graphql types, like fields not being iterable, null vs non-nulls, etc. I'm not sure why, some other autogenerated resolvers work just fine. I haven't identified a pattern. And as the autogenerated files are the same, it looks like something changed on the Prisma client that makes the queries return a different structure.

Inspecting the extension, I notice that he creates the replicas using this:

const PrismaClient = Object.getPrototypeOf(client).constructor

From the wrapped client, maybe this is the issue.

Has anybody had luck using the Read Replicas plugin?

[alacret]

It looks like the extended client is unable to solve relations like the Graphql API is intending