Add documentation on how to use prisma client extensions for "enum"-like validation about epic-stack

[kasperpeulen]

For people looking for it.

You can make client extensions like this:

import { z } from "zod";
import { Prisma } from "@prisma/client";

const schema = z.object({
  slug: z
    .string()
    .max(100)
    .regex(/^[a-z0-9]+(?:-[a-z0-9]+)*$/),
  name: z.string().max(100),
  description: z.string().max(1000),
  price: z
    .instanceof(Prisma.Decimal)
    .refine((price) => price.gte("0.01") && price.lt("1000000.00")),
}) satisfies z.Schema<Prisma.ProductUncheckedCreateInput>;

export const ProductValidation = Prisma.defineExtension({
  query: {
    product: {
      create({ args, query }) {
        args.data = schema.parse(args.data);
        return query(args);
      },
      update({ args, query }) {
        args.data = schema.partial().parse(args.data);
        return query(args);
      },
      updateMany({ args, query }) {
        args.data = schema.partial().parse(args.data);
        return query(args);
      },
      upsert({ args, query }) {
        args.create = schema.parse(args.create);
        args.update = schema.partial().parse(args.update);
        return query(args);
      },
    },
  },
});

And then use it like this:

import { Prisma, PrismaClient } from "@prisma/client";
import { ProductValidation } from "./models/product";
import { ReviewValidation } from "./models/review";

const prisma = new PrismaClient()
  .$extends(ProductValidation)
  .$extends(ReviewValidation);

See:
https://github.com/prisma/prisma-client-extensions/blob/main/input-validation/README.md

[Pablets]

As stated here prisma/prisma#2219 (comment) this feature its not being developed in the future, maybe never, neither with check constraints or with any other method.
Here is another documentation explainig why they are opting-ing strictly for db-native features.
prisma/specs#330 (comment)
Some other native features are also not in the roadmap from the time beign e.g. JSON field type support: prisma/prisma#3786

[kentcdodds]

As noted, I'm talking about using Prisma client extensions feature which does mean this wouldn't be a database-level enhancement, but just one for the client which is sufficient for us.

[kentcdodds]

Thanks @L-Steinmacher!