Custom validation Libraries without using raw requests

[neronim1141]

HI! First of all thank you for creating and opensourcing this amazing library, I'm new to microservices and was looking backend framework simmilar to this for quite a long time.

The only problem I'm struggling with is the validation setup based on interfaces:

zod/drizzle infer types aren't working,

directly returning Promise<User> is not working, first we need to wrap it in some Result<T> { result:T } which in my opinion can clutter response

Unions dont work Promise<User|Error> resulting in interface with optional fields even thought they will be not present

all of this result in specificaly asserting all responses usually with:

Promise<{
  success:boolean, // clutter we have error codes only for the Fronted to check messages or data based on it (even though we should be able to use status code)
  message?:string  // field should be present if http code is error code
  data?: User          // field should be present if 2xx code is present 
}

Looking at that i would like to propose additional api parameter called schema
that can work with for example zod:

import 'zod-openapi/extend';
import { z } from 'zod';
import { api, EncoreZodOpenApiSchema} from "encore.dev/api";

  schema: {
    body: z.object({
      jobId: z.string().openapi({
        description: 'Job ID',
        example: '60002023',
      }),
    }),
    response: {
      201: z.object({
        jobId: z.string().openapi({
          description: 'Job ID',
          example: '60002023',
        }),
      }),
    },
 } satisfies EncoreZodOpenApiSchema,

the body, header, response types can be directly infered from zod without manually asserting them in the api handler

I think this would allow us to compose our validations in a much cleaner way and also integrate with other libraries like
drizzle-zod giving us more options to customize response details

I uderstand that it would require a lot of code changes so im not expecting it to happen, just noticed few problems with current approach that i would like to address

[marcuskohlberg]

Thanks for the suggestion.
Is there something with the built-in validation (https://encore.dev/docs/ts/primitives/validation) that you found not suitable to your use case? It's much more performant than using Zod since it's part of Encore's rust runtime.

[neronim1141]

I get that its more performant, and i agree with that but its also very limiting,

what about the situation where you have queryparam and body named the same?
what if you want to have two dimensional array of strings 3x3 as body parameter
what if you want to use discriminative unions
cannot use drizzle with drizzlezod because the validation is not parsed properly

there is a bunch of other problems that i can see with that approach which zod or other libraries of that type are solving with their extensive toolbox.
And yes we can use raw requests and parse it inside but then we are losing the ability to make documentation like in your validation

maybe adding possibility to use schema input output as parameter to api.raw would solve those issues