Validation

You can validate procedure handler arguments by providing a validation schema to your procedure handler.

Validating your handler

Earlier in our quick start guide, we created a new Aetheris server and defined a base router, but none of our handlers take any input or have any validation. Let's expand on what we created so that we can validate the users input.

import { createAetheris, router } from "@aetheris/server";
import { z } from "zod";
 
const aether = createAetheris();
 
export const app = router({
    helloWorld: aether.handler({
        input: z.object({
            name: z.string(),
        }),
        resolve: async ({ input }) => {
            return `Hello, ${input}!`;
        },
    }),
});
 
export type App = typeof app;

The validation schema will now validate that the input object has a name property that is a string. If the input object does not match the schema, the procedure will throw an error when resolving.

The type inference from our schema will carry over to our router type, allowing the client to know what the input object should look like. Here is what our current router type looks like.

type Router = {
    helloWorld: Resolver<{
        input: {
            name: string;
        };
        output: {
            message: string;
        };
    }>;
}

Validation can also be used to validate the output of a procedure. By default the return type is inferred from the return value of the resolver, but if you provide a output schema, the return value will be validated against the schema and the schema will be used instead of the inferred return value.

export const app = router({
    users: {
        getUser: aether.handler({
            input: z.object({
                id: z.string(),
            }),
            output: z.object({
                id: z.string(),
                name: z.string(),
            }),
            resolve: async ({ input }) => {
                return {
                    id: input.id,
                    name: "John Doe",
                };
            },
        }),
    },
}