Theo's Typesafe CultTTC
Theo's Typesafe Cult•2y ago
noynek2242

Sharing Logic Across TRPC Procedures

I've got multiple procedures that need to share logic. For example, I've got a query and a mutation that both return a lastUpdatedBy field. Instead of returning the user id, I return their name.
Technically, I've been able to write the code within both the query and mutation, but I'm struggling to find a way to share that logic.

The main issue is really a Typescript one where I can't figure out how to 
  getSomething: protectedProcedure
    .input(z.object({ id: z.string() }))
    .query(async ({ ctx, input }) => {
      let something = await ctx.db.somethings.findUnique({
        where: {
          id: parseInt(input.id),
        },
      });

      // here's where I want to write some shared logic
      something = await processSomething({ something, db: ctx.db });


The challenge I'm stuck on is figuring out the types in my util. I was able to get the prisma types, but not the something types.
type Props = {
  db: PrismaClient<Prisma.PrismaClientOptions, never, DefaultArgs>;
  something: ???
}
function processSomething({something, db}: Props) {}


I've tried this approach https://trpc.io/docs/client/vanilla/infer-types with something like
type RouterOutput = inferRouterOutputs<AppRouter>;
type Home = RouterOutput["something"]["getSomething"];

But that produces an error
'something' is referenced directly or indirectly in its own type annotation.

Any suggestions? thanks!
Inferring Types | tRPC
It is often useful to access the types of your API within your clients. For this purpose, you are able to infer the types contained in your AppRouter.
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