Fix tune TS errors

Author: stevegalili

examples/cookbook/app/network-requests/PhoneBook.tsx

@@ -25,7 +25,8 @@ export default () => {
       try {
         await Promise.all([_getAllContacts(), _getAllFavorites()]);
       } catch (e) {
-        setError(e.message);
+        const message = e instanceof Error ? e.message : JSON.stringify(e);
+        setError(message);
       }
     };
 

examples/cookbook/app/network-requests/__tests__/PhoneBook.test.tsx

@@ -8,7 +8,7 @@ jest.mock('axios');
 
 describe('PhoneBook', () => {
   it('fetches contacts successfully and renders in list', async () => {
-    (global.fetch as jest.SpyInstance).mockResolvedValueOnce({
+    (global.fetch as jest.Mock).mockResolvedValueOnce({
       ok: true,
       json: jest.fn().mockResolvedValueOnce(DATA),
     });
@@ -22,7 +22,7 @@ describe('PhoneBook', () => {
   });
 
   it('fails to fetch contacts and renders error message', async () => {
-    (global.fetch as jest.SpyInstance).mockResolvedValueOnce({
+    (global.fetch as jest.Mock).mockResolvedValueOnce({
       ok: false,
     });
     (axios.get as jest.Mock).mockResolvedValue({ data: DATA });
@@ -33,7 +33,7 @@ describe('PhoneBook', () => {
   });
 
   it('fetches favorites successfully and renders all users avatars', async () => {
-    (global.fetch as jest.SpyInstance).mockResolvedValueOnce({
+    (global.fetch as jest.Mock).mockResolvedValueOnce({
       ok: true,
       json: jest.fn().mockResolvedValueOnce(DATA),
     });
@@ -46,7 +46,7 @@ describe('PhoneBook', () => {
   });
 
   it('fails to fetch favorites and renders error message', async () => {
-    (global.fetch as jest.SpyInstance).mockResolvedValueOnce({
+    (global.fetch as jest.Mock).mockResolvedValueOnce({
       ok: true,
       json: jest.fn().mockResolvedValueOnce(DATA),
     });

website/docs/12.x/cookbook/network-requests/fetch.md

@@ -199,7 +199,7 @@ See MDN's [docs](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Usin
 ...
 it('fails to fetch contacts and renders error message', async () => {
   // mock the fetch function to be not ok which will throw an error
-  (global.fetch as jest.SpyInstance).mockResolvedValueOnce({
+  (global.fetch as jest.Mock).mockResolvedValueOnce({
     ok: false,
   });
   render(<PhoneBook/>);