zodtrpc

trpc error Input parser must be a ZodObject

I have the following input schema:

const inputSchema = z.union([
  z.object({
    id: z.string(),
  }),
  z.object({
    key: z.string(),
  }),
])

This schema works until I do:

import { generateOpenApiDocument } from 'trpc-openapi'

const openApiDocument = generateOpenApiDocument(trpcAppRouter, {
  title: 'title',
  baseUrl: '/route',
  version: '0.0.1',
})

When I generate pass the route with the input to generateOpenApiDocument then I get the error:

TRPCError: [query.thing.route] - Input parser must be a ZodObject

I guess it's a bug in generateOpenApiDocument that doesn't check the input correctly because it is a ZodObject but I'm not sure how to work around this.

Solution

  • I found that trpc-opeapi uses zod-to-json-schema and zod-to-json-schema does not support union. Hence trpc-openapi does not support OpenAPI 3 spec.