docs(cookbook): network requests recipes (#1655)

* squash prev commits

* remove unneeded axios mock

* set maxWorkers=2

* run with a slow test reporter

* revert: run with a slow test reporter

* Add url check to mock and further reading and alternatives

* use MSW for all API calls in cookbook test suits

* Comments with implem. explanation

* Arrange docs initially to reflect new scenario and remove jest.setTimeout

* updating docs (1)

* updating docs (2)

* updating docs with global guarding and conclusion

---------

Co-authored-by: stevegalili <steve.galili@mywheels.nl>

examples/cookbook/app/index.tsx

@@ -82,6 +82,7 @@ type Recipe = {
 };
 
 const recipes: Recipe[] = [
-  { id: 2, title: 'Welcome Screen with Custom Render', path: 'custom-render/' },
-  { id: 1, title: 'Task List with Jotai', path: 'jotai/' },
+  { id: 1, title: 'Welcome Screen with Custom Render', path: 'custom-render/' },
+  { id: 2, title: 'Task List with Jotai', path: 'state-management/jotai/' },
+  { id: 3, title: 'Phone book with\na Variety of Net. Req. Methods', path: 'advanced/' },
 ];

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

@@ -0,0 +1,52 @@
+import React, { useEffect, useState } from 'react';
+import { Text } from 'react-native';
+import { User } from './types';
+import ContactsList from './components/ContactsList';
+import FavoritesList from './components/FavoritesList';
+import getAllContacts from './api/getAllContacts';
+import getAllFavorites from './api/getAllFavorites';
+
+export default () => {
+  const [usersData, setUsersData] = useState<User[]>([]);
+  const [favoritesData, setFavoritesData] = useState<User[]>([]);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    const _getAllContacts = async () => {
+      const _data = await getAllContacts();
+      setUsersData(_data);
+    };
+    const _getAllFavorites = async () => {
+      const _data = await getAllFavorites();
+      setFavoritesData(_data);
+    };
+
+    const run = async () => {
+      try {
+        await Promise.all([_getAllContacts(), _getAllFavorites()]);
+      } catch (e) {
+        const message = isErrorWithMessage(e) ? e.message : 'Something went wrong';
+        setError(message);
+      }
+    };
+
+    void run();
+  }, []);
+
+  if (error) {
+    return <Text>An error occurred: {error}</Text>;
+  }
+
+  return (
+    <>
+      <FavoritesList users={favoritesData} />
+      <ContactsList users={usersData} />
+    </>
+  );
+};
+
+const isErrorWithMessage = (
+  e: unknown,
+): e is {
+  message: string;
+} => typeof e === 'object' && e !== null && 'message' in e;

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

@@ -0,0 +1,40 @@
+import { render, screen, waitForElementToBeRemoved } from '@testing-library/react-native';
+import React from 'react';
+import PhoneBook from '../PhoneBook';
+import {
+  mockServerFailureForGetAllContacts,
+  mockServerFailureForGetAllFavorites,
+} from './test-utils';
+
+jest.setTimeout(10000);
+
+describe('PhoneBook', () => {
+  it('fetches all contacts and favorites successfully and renders lists in sections correctly', async () => {
+    render(<PhoneBook />);
+
+    await waitForElementToBeRemoved(() => screen.getByText(/users data not quite there yet/i));
+    expect(await screen.findByText('Name: Mrs Ida Kristensen')).toBeOnTheScreen();
+    expect(await screen.findByText('Email: ida.kristensen@example.com')).toBeOnTheScreen();
+    expect(await screen.findAllByText(/name/i)).toHaveLength(3);
+    expect(await screen.findByText(/my favorites/i)).toBeOnTheScreen();
+    expect(await screen.findAllByLabelText('favorite-contact-avatar')).toHaveLength(3);
+  });
+
+  it('fails to fetch all contacts and renders error message', async () => {
+    mockServerFailureForGetAllContacts();
+    render(<PhoneBook />);
+
+    await waitForElementToBeRemoved(() => screen.getByText(/users data not quite there yet/i));
+    expect(
+      await screen.findByText(/an error occurred: error fetching contacts/i),
+    ).toBeOnTheScreen();
+  });
+
+  it('fails to fetch favorites and renders error message', async () => {
+    mockServerFailureForGetAllFavorites();
+    render(<PhoneBook />);
+
+    await waitForElementToBeRemoved(() => screen.getByText(/figuring out your favorites/i));
+    expect(await screen.findByText(/error fetching favorites/i)).toBeOnTheScreen();
+  });
+});

examples/cookbook/app/network-requests/__tests__/test-utils.ts

@@ -0,0 +1,109 @@
+import { User } from '../types';
+import {http, HttpResponse} from "msw";
+import {setupServer} from "msw/node";
+
+// Define request handlers and response resolvers for random user API.
+// By default, we always return the happy path response.
+const handlers = [
+  http.get('https://randomuser.me/api/*', () => {
+    return HttpResponse.json(DATA);
+  }),
+];
+
+export const server = setupServer(...handlers);
+
+export const mockServerFailureForGetAllContacts = () => {
+  server.use(
+    http.get('https://randomuser.me/api/', ({ request }) => {
+      // Construct a URL instance out of the intercepted request.
+      const url = new URL(request.url);
+      // Read the "results" URL query parameter using the "URLSearchParams" API.
+      const resultsLength = url.searchParams.get('results');
+      // Simulate a server error for the get all contacts request.
+      // We check if the "results" query parameter is set to "25"
+      // to know it's the correct request to mock, in our case get all contacts.
+      if (resultsLength === '25') {
+        return new HttpResponse(null, { status: 500 });
+      }
+
+      return HttpResponse.json(DATA);
+    }),
+  );
+};
+
+export const mockServerFailureForGetAllFavorites = () => {
+  server.use(
+    http.get('https://randomuser.me/api/', ({ request }) => {
+      // Construct a URL instance out of the intercepted request.
+      const url = new URL(request.url);
+      // Read the "results" URL query parameter using the "URLSearchParams" API.
+      const resultsLength = url.searchParams.get('results');
+      // Simulate a server error for the get all favorites request.
+      // We check if the "results" query parameter is set to "10"
+      // to know it's the correct request to mock, in our case get all favorites.
+      if (resultsLength === '10') {
+        return new HttpResponse(null, { status: 500 });
+      }
+
+      return HttpResponse.json(DATA);
+    }),
+  );
+};
+export const DATA: { results: User[] } = {
+  results: [
+    {
+      name: {
+        title: 'Mrs',
+        first: 'Ida',
+        last: 'Kristensen',
+      },
+      email: 'ida.kristensen@example.com',
+      id: {
+        name: 'CPR',
+        value: '250562-5730',
+      },
+      picture: {
+        large: 'https://randomuser.me/api/portraits/women/26.jpg',
+        medium: 'https://randomuser.me/api/portraits/med/women/26.jpg',
+        thumbnail: 'https://randomuser.me/api/portraits/thumb/women/26.jpg',
+      },
+      cell: '123-4567-890',
+    },
+    {
+      name: {
+        title: 'Mr',
+        first: 'Elijah',
+        last: 'Ellis',
+      },
+      email: 'elijah.ellis@example.com',
+      id: {
+        name: 'TFN',
+        value: '138117486',
+      },
+      picture: {
+        large: 'https://randomuser.me/api/portraits/men/53.jpg',
+        medium: 'https://randomuser.me/api/portraits/med/men/53.jpg',
+        thumbnail: 'https://randomuser.me/api/portraits/thumb/men/53.jpg',
+      },
+      cell: '123-4567-890',
+    },
+    {
+      name: {
+        title: 'Mr',
+        first: 'Miro',
+        last: 'Halko',
+      },
+      email: 'miro.halko@example.com',
+      id: {
+        name: 'HETU',
+        value: 'NaNNA945undefined',
+      },
+      picture: {
+        large: 'https://randomuser.me/api/portraits/men/17.jpg',
+        medium: 'https://randomuser.me/api/portraits/med/men/17.jpg',
+        thumbnail: 'https://randomuser.me/api/portraits/thumb/men/17.jpg',
+      },
+      cell: '123-4567-890',
+    },
+  ],
+};

examples/cookbook/app/network-requests/api/getAllContacts.ts

@@ -0,0 +1,10 @@
+import { User } from '../types';
+
+export default async (): Promise<User[]> => {
+  const res = await fetch('https://randomuser.me/api/?results=25');
+  if (!res.ok) {
+    throw new Error(`Error fetching contacts`);
+  }
+  const json = await res.json();
+  return json.results;
+};

examples/cookbook/app/network-requests/api/getAllFavorites.ts

@@ -0,0 +1,10 @@
+import { User } from '../types';
+
+export default async (): Promise<User[]> => {
+  const res = await fetch('https://randomuser.me/api/?results=10');
+  if (!res.ok) {
+    throw new Error(`Error fetching favorites`);
+  }
+  const json = await res.json();
+  return json.results;
+};

examples/cookbook/app/network-requests/components/ContactsList.tsx

@@ -0,0 +1,60 @@
+import { FlatList, Image, StyleSheet, Text, View } from 'react-native';
+import React, { useCallback } from 'react';
+import type { ListRenderItem } from '@react-native/virtualized-lists';
+import { User } from '../types';
+
+export default ({ users }: { users: User[] }) => {
+  const renderItem: ListRenderItem<User> = useCallback(
+    ({ item: { name, email, picture, cell }, index }) => {
+      const { title, first, last } = name;
+      const backgroundColor = index % 2 === 0 ? '#f9f9f9' : '#fff';
+      return (
+        <View style={[{ backgroundColor }, styles.userContainer]}>
+          <Image source={{ uri: picture.thumbnail }} style={styles.userImage} />
+          <View>
+            <Text>
+              Name: {title} {first} {last}
+            </Text>
+            <Text>Email: {email}</Text>
+            <Text>Mobile: {cell}</Text>
+          </View>
+        </View>
+      );
+    },
+    [],
+  );
+
+  if (users.length === 0) return <FullScreenLoader />;
+
+  return (
+    <View>
+      <FlatList<User>
+        data={users}
+        renderItem={renderItem}
+        keyExtractor={(item, index) => `${index}-${item.id.value}`}
+      />
+    </View>
+  );
+};
+const FullScreenLoader = () => {
+  return (
+    <View style={styles.loaderContainer}>
+      <Text>Users data not quite there yet...</Text>
+    </View>
+  );
+};
+
+const styles = StyleSheet.create({
+  userContainer: {
+    padding: 16,
+    flexDirection: 'row',
+    alignItems: 'center',
+  },
+  userImage: {
+    width: 50,
+    height: 50,
+    borderRadius: 24,
+    marginRight: 16,
+  },
+  loaderContainer: { flex: 1, justifyContent: 'center', alignItems: 'center' },
+});

examples/cookbook/app/network-requests/components/FavoritesList.tsx

@@ -0,0 +1,59 @@
+import { FlatList, Image, StyleSheet, Text, View } from 'react-native';
+import React, { useCallback } from 'react';
+import type { ListRenderItem } from '@react-native/virtualized-lists';
+import { User } from '../types';
+
+export default ({ users }: { users: User[] }) => {
+  const renderItem: ListRenderItem<User> = useCallback(({ item: { picture } }) => {
+    return (
+      <View style={styles.userContainer}>
+        <Image
+          source={{ uri: picture.thumbnail }}
+          style={styles.userImage}
+          accessibilityLabel={'favorite-contact-avatar'}
+        />
+      </View>
+    );
+  }, []);
+
+  if (users.length === 0) return <FullScreenLoader />;
+
+  return (
+    <View style={styles.outerContainer}>
+      <Text>⭐My Favorites</Text>
+      <FlatList<User>
+        horizontal
+        showsHorizontalScrollIndicator={false}
+        data={users}
+        renderItem={renderItem}
+        keyExtractor={(item, index) => `${index}-${item.id.value}`}
+      />
+    </View>
+  );
+};
+const FullScreenLoader = () => {
+  return (
+    <View style={styles.loaderContainer}>
+      <Text>Figuring out your favorites...</Text>
+    </View>
+  );
+};
+
+const styles = StyleSheet.create({
+  outerContainer: {
+    padding: 8,
+  },
+  userContainer: {
+    padding: 8,
+    flexDirection: 'row',
+    alignItems: 'center',
+  },
+  userImage: {
+    width: 52,
+    height: 52,
+    borderRadius: 36,
+    borderColor: '#9b6dff',
+    borderWidth: 2,
+  },
+  loaderContainer: { height: 52, justifyContent: 'center', alignItems: 'center' },
+});

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

@@ -0,0 +1,6 @@
+import * as React from 'react';
+import PhoneBook from './PhoneBook';
+
+export default function Example() {
+  return <PhoneBook />;
+}

examples/cookbook/app/network-requests/types.ts

@@ -0,0 +1,18 @@
+export type User = {
+  name: {
+    title: string;
+    first: string;
+    last: string;
+  };
+  email: string;
+  id: {
+    name: string;
+    value: string;
+  };
+  picture: {
+    large: string;
+    medium: string;
+    thumbnail: string;
+  };
+  cell: string;
+};

examples/cookbook/jest-setup.ts

@@ -2,6 +2,14 @@
 
 // Import built-in Jest matchers
 import '@testing-library/react-native/extend-expect';
+import { server } from './app/network-requests/__tests__/test-utils';
 
 // Silence the warning: Animated: `useNativeDriver` is not supported because the native animated module is missing
 jest.mock('react-native/Libraries/Animated/NativeAnimatedHelper');
+
+// Enable API mocking via Mock Service Worker (MSW)
+beforeAll(() => server.listen());
+// Reset any runtime request handlers we may add during the tests
+afterEach(() => server.resetHandlers());
+// Disable API mocking after the tests are done
+afterAll(() => server.close());