feat(core/db): allow to extend PrismaClient

[iamandrewluca]

Using this feature, one can extend PrismaClient, and add for example hooks at prisma level

export default withAuth(
  config<TypeInfo>({
    db: {
      extendPrismaClient(client: PrismaClient) {
        return client.$extends({
          query: {
            async $allOperations({ operation, model, args, query }) {
              // Raw Query is executed
              if (model === undefined) {
                const result: unknown = await query(args);
                return result;
              }

              const hooks = getPrismaHooks(model, operation);

              await hooks?.before?.(client, args);
              const result: unknown = await query(args);
              await hooks?.after?.(client, args, result);

              return result;
            },
          },
        });
      },
    },
  }),
);

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[gautamsi]

I was looking to integrate @prisma/extension-read-replicas with this yesterday, right on time!
hope this gets into the release.

[iamandrewluca]

We are already using this with a patch on top of KS

[dcousens]

LGTM, doesn't resolve the issues raised by #8847, but I think we'll look at that another day - and there exists a workaround for that

[dcousens]

Thanks @iamandrewluca! I'll try and release this asap

[iamandrewluca]

Thanks! That is great!

[gautamsi]

@iamandrewluca can you share the code of getPrismaHooks or is this exported by prisma?

[iamandrewluca]

I have a big object mapper for all models/operations/lifecycles, and getPrismaHooks returns me the functions based on model/operation

import { type PrismaClient, type Prisma } from '@prisma/client';
import type { TypeInfo } from '.keystone/types';

type PrismaHook = (
	prismaClient: PrismaClient,
	args: unknown,
) => Promise<void> | Promise<unknown>;

type PrismaExtendedOperation = {
	[ListType in keyof TypeInfo['lists']]?: {
		[OperationType in Prisma.DMMF.ModelAction]?: Partial<
			Record<'before' | 'after', PrismaHook>
		>;
	};
};

const PrismaHooks: PrismaExtendedOperation = {
	Order: {
		create: {
			before: async (prismaClient: PrismaClient, args: unknown) => {
				// ...
			},
		},
		update: {
			before: async (prismaClient: PrismaClient, args: unknown) => {
				// ...
			},
		},
	},
};

export function getPrismaHooks(
	model: keyof TypeInfo['lists'],
	operation: string,
): Partial<Record<'before' | 'after', PrismaHook>> | undefined {
	const modelHooks = PrismaHooks[model];
	return modelHooks?.[operation as Prisma.DMMF.ModelAction];
}

[dcousens]

@iamandrewluca out of interest, why use these by comparison to the Keystone hooks?

[iamandrewluca]

@dcousens, we had to create custom GQL mutations that use Prisma transactions, and doing that KS hooks did not work.