isFirefox

1/**
2 * Determines if the current browser is Firefox.
3 *
4 * @returns True if running in Firefox, false otherwise.
5 */
6export function isFirefox(): boolean {
7  if (typeof navigator === 'undefined') return false;
8  return /firefox/i.test(navigator.userAgent);
9}

1const originalNavigator = global.navigator;
2
3afterEach(() => {
4  global.navigator = originalNavigator;
5});
6
7test('returns true for Firefox userAgent', () => {
8  // @ts-ignore
9  global.navigator = {
10    userAgent: 'Mozilla/5.0 (Windows NT 10.0; rv:92.0) Gecko/20100101 Firefox/92.0'
11  };
12  expect(isFirefox()).toBe(true);
13});
14
15test('returns false for Chrome userAgent', () => {
16  // @ts-ignore
17  global.navigator = {
18    userAgent:
19      'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/96.0.4664.45 Safari/537.36'
20  };
21  expect(isFirefox()).toBe(false);
22});
23
24test('returns false if navigator is undefined', () => {
25  // @ts-ignore
26  delete global.navigator;
27  expect(isFirefox()).toBe(false);
28});