Using Fetch with Zod in a 2 step request Factory

createFetch.ts

import type { ZodTypeAny, z } from 'zod';

//@see https://zod.dev/?id=writing-generic-functions
export const createFetch = <Output extends ZodTypeAny>(
  zodSchema: Output
): ((input: RequestInfo | URL, init?: RequestInit) => Promise<z.infer<Output>>) => {
  return (input, init) =>
    fetch(input, init).then((res) => {
      if (!res.ok) {
        throw new Error(res.statusText);
      }
      return res.json().then((data: unknown) => {
        const result = zodSchema.safeParse(data);
        if (result.success) {
          return result.data as z.infer<Output>;
        } else {
          throw result.error.format();
        }
      });
    });
};

// inside an async fn: 
const get = createFetch<typeof YOUR_ZOD_SCHEMA_OBJECT>(YOUR_ZOD_SCHEMA_OBJECT);
try {
  const result = await get('/some-url')
  // carry on you have the parsed data now
} catch(e) {  // deal with it }