NotZelda•4w ago

Is there a typescript performance gain if I infer my router outputs once, and then export them?

You can infer your router outputs using RouterOutputs["router"]["procedure"]. Should I just use this directly on the objects I want to pass this type through, or should I declare these once in a RouterOutputs file, and export a named type? Potentially if the traversal of the RouterOutputs type helper is expensive typescript could cache this result easier with a named export. Im just not sure if this is a reality or best practice?

1 Reply

NotZeldaOP•4w ago

The example from the docs:

// @filename: client.ts
import type { inferRouterInputs, inferRouterOutputs } from '@trpc/server';
import type { AppRouter } from './server';
 
type RouterInput = inferRouterInputs<AppRouter>;
type RouterOutput = inferRouterOutputs<AppRouter>;
 
type PostCreateInput = RouterInput['post']['create'];         
//^ type PostCreateInput = {
//    title: string;
//    text: string;
//   }
type PostCreateOutput = RouterOutput['post']['create'];
            
//^ type PostCreateOutput = AsyncIterable<Serialize<$T>, Serialize<$Return>, Serialize<$Next>>

// @filename: client.ts
import type { inferRouterInputs, inferRouterOutputs } from '@trpc/server';
import type { AppRouter } from './server';
 
type RouterInput = inferRouterInputs<AppRouter>;
type RouterOutput = inferRouterOutputs<AppRouter>;
 
type PostCreateInput = RouterInput['post']['create'];         
//^ type PostCreateInput = {
//    title: string;
//    text: string;
//   }
type PostCreateOutput = RouterOutput['post']['create'];
            
//^ type PostCreateOutput = AsyncIterable<Serialize<$T>, Serialize<$Return>, Serialize<$Next>>

Is there a typescript performance gain if I infer my router outputs once, and then export them?

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