blog_useFetch.ts

import { useState, useEffect, useCallback } from "react";

interface RequestProps<T> {
  url: RequestInfo;
  init?: RequestInit;
  processData?: (data: any) => T;
}

export const useFetch = <T>({ url, init, processData }: RequestProps<T>) => {
  // Response state
  const [data, setData] = useState<T>();

  // Turn objects into strings for useCallback & useEffect dependencies
  const [stringifiedUrl, stringifiedInit] = [JSON.stringify(url), JSON.stringify(init)];

  // If no processing function is passed just cast the object to type T
  // The callback hook ensures that the function is only created once
  // and hence the effect hook below doesn't start an infinite loop
  const processJson = useCallback(processData || ((jsonBody: any) => jsonBody as T), []);

  useEffect(() => {
    // Define asynchronous function
    const fetchApi = async () => {
      try {
        // Fetch data from REST API
        const response = await fetch(url, init);

        if (response.status === 200) {
          // Extract json
          const rawData: any = await response.json();
          const processedData = processJson(rawData);
          setData(processedData);
        } else {
          console.error(`Error ${response.status} ${response.statusText}`);
        }
      } catch (error) {
        console.error(`Error ${error}`);
      }
    };

    // Call async function
    fetchApi();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [stringifiedUrl, stringifiedInit, processJson]);

  return data;
};

blog_useFetch_DogImage.tsx

// DogImage.tsx
import React, { FC } from "react";
import { useFetch } from "./useFetch";

type DogImageType = { message: string; status: string };

export const DogImage: FC = () => {
  const data = useFetch<DogImageType>({
    url: "https://dog.ceo/api/breed/beagle/images/random"
  });

  return <>{data ? <img src={data.message} alt="dog"></img> : <div>Loading</div>}</>;
};