Alex•13mo ago

Running TRPC on Vercel with custom serialization fails

Hi all, I'm having some difficulties with the serialization of my objects when I run on vercel. I'm running nextjs 13.4.4 with trpc/server,client,next 10.28.1 and the next page routing. I'm using a custom type "ts-money" which is returned in a trpc response like:

getSalaryEnvironment: protectedProcedure
    .input(
      z.object({
        administratorId: z.string(),
        salaryDate: salaryDateSchema,
      }),
    )
    .query(async ({ input }) => {
      return {
        date: new Date(2023, 5, 31),
        nbrOfDaysWorked: 20,
        salaryDate: input.salaryDate,
        totalGrossIncomeFromPreviousSalaryInYear: new Money(6000000,Currencies.EUR),
      }
    }),

getSalaryEnvironment: protectedProcedure
    .input(
      z.object({
        administratorId: z.string(),
        salaryDate: salaryDateSchema,
      }),
    )
    .query(async ({ input }) => {
      return {
        date: new Date(2023, 5, 31),
        nbrOfDaysWorked: 20,
        salaryDate: input.salaryDate,
        totalGrossIncomeFromPreviousSalaryInYear: new Money(6000000,Currencies.EUR),
      }
    }),

3 Replies

Alex•13mo ago

I have implemented a custom serialization for it like so:

import { Money } from 'ts-money'
import { z } from 'zod'

const moneySchema = z.object({
  amount: z.number(),
  currency: z.union([z.literal('EUR'), z.literal('USD'), z.literal('GBP')]),
})
export const initializeSuperJson = () => {
  superjson.registerCustom(
    {
      isApplicable: (m): m is Money => {
        return moneySchema.safeParse(m).success
      },
      serialize: (m: Money) => {
        return { amount: m.amount, currency: m.currency }
      },
      deserialize: (json: { amount: number; currency: string }) => {
        return new Money(json.amount, json.currency)
      },
    },
    'Money',
  )
}

import { Money } from 'ts-money'
import { z } from 'zod'

const moneySchema = z.object({
  amount: z.number(),
  currency: z.union([z.literal('EUR'), z.literal('USD'), z.literal('GBP')]),
})
export const initializeSuperJson = () => {
  superjson.registerCustom(
    {
      isApplicable: (m): m is Money => {
        return moneySchema.safeParse(m).success
      },
      serialize: (m: Money) => {
        return { amount: m.amount, currency: m.currency }
      },
      deserialize: (json: { amount: number; currency: string }) => {
        return new Money(json.amount, json.currency)
      },
    },
    'Money',
  )
}

It is injected in my singleton client (Using T3 approach) like so:

/**
 * A set of typesafe react-query hooks for your tRPC API
 */
export const api = createTRPCNext<AppRouter>({
  config() {
    initializeSuperJson()
    return {
      /**
       * Transformer used for data de-serialization from the server
       * @see https://trpc.io/docs/data-transformers
       **/
      transformer: superjson,

      /**
       * Links used to determine request flow from client to server
       * @see https://trpc.io/docs/links
       * */
      links: [
        loggerLink({
          enabled: (opts) =>
            process.env.NODE_ENV === 'development' ||
            (opts.direction === 'down' && opts.result instanceof Error),
        }),
        httpBatchLink({
          url: `${getBaseUrl()}/api/trpc`,
        }),
      ],
    }
  },

/**
 * A set of typesafe react-query hooks for your tRPC API
 */
export const api = createTRPCNext<AppRouter>({
  config() {
    initializeSuperJson()
    return {
      /**
       * Transformer used for data de-serialization from the server
       * @see https://trpc.io/docs/data-transformers
       **/
      transformer: superjson,

      /**
       * Links used to determine request flow from client to server
       * @see https://trpc.io/docs/links
       * */
      links: [
        loggerLink({
          enabled: (opts) =>
            process.env.NODE_ENV === 'development' ||
            (opts.direction === 'down' && opts.result instanceof Error),
        }),
        httpBatchLink({
          url: `${getBaseUrl()}/api/trpc`,
        }),
      ],
    }
  },

When I run it locally everything works as expected... But when deployed on vercel the custome serialization is not executed. I have added some logging and I can see the injection of custom serialization happening the first time I use a trpc route api.xxxx But the custom serilization does not take place. Any idea where I could start digging?

julius•13mo ago

Check here https://github.com/trpc/trpc/blob/next13-auth/examples/next-13-starter/src/trpc/shared.ts

GitHub

trpc/examples/next-13-starter/src/trpc/shared.ts at next13-auth · t...

🧙‍♀️ Move Fast and Break Nothing. End-to-end typesafe APIs made easy. - trpc/examples/next-13-starter/src/trpc/shared.ts at next13-auth · trpc/trpc

Alex•13mo ago

Hi Julius, I will try this. Thanks for sharing.👍 This did resolve my issue. thanks for sharring this example.