How can i add conditional defaults to an object?

[refuse2speak]

Hey, i have a form schema for which i would like to have defaults for schema when the app runs in testing environment. How could i achieve this in a more dry way?

Thanks for your help!

import { z } from 'zod';
import { IsProduction, Runtime } from '$lib/registration/Runtime';

const RegistrationFormSchema = z.object({
	firstname: z.string(),
	lastname: z.string()
});

const RegistrationSchemaDefaults = z.object({
	firstname: z.string()
		.default('John'),
	lastname: z.string()
		.default('Doe'),
});

export const GetRegistrationSchema = (runtime: Runtime) => {
	return IsProduction(runtime)
		? RegistrationFormSchema
		: RegistrationSchemaDefaults;
};

export type Registration = z.infer<typeof RegistrationFormSchema>;