chore: Adds Test Cases for Auth onFail flow

src/screens/LoginScreen.test.tsx

@@ -1,15 +1,27 @@
 import React from 'react';
 import { Text } from 'react-native';
-import { render } from '@testing-library/react-native';
+import { render, act } from '@testing-library/react-native';
 import { Provider as PaperProvider } from 'react-native-paper';
 import { useStyles, useDeveloperConfig, usePendingInvite } from '../hooks';
 import { LoginScreen } from './LoginScreen';
+import * as OAuthLoginButtonModule from '../components/OAuthLoginButton';
 
 jest.mock('../hooks', () => ({
   useStyles: jest.fn(),
   useDeveloperConfig: jest.fn(),
   usePendingInvite: jest.fn(),
 }));
+jest.mock('react-native-paper', () => {
+  const Dialog = ({ visible, children }: any) => visible && children;
+  Dialog.Icon = jest.fn();
+  Dialog.Title = Text;
+  Dialog.Content = ({ children }: any) => children;
+
+  return {
+    ...jest.requireActual('react-native-paper'),
+    Dialog,
+  };
+});
 
 const useDeveloperConfigMock = useDeveloperConfig as jest.Mock;
 const useStylesMock = useStyles as jest.Mock;
@@ -66,4 +78,53 @@ describe('LoginScreen', () => {
 
     expect(getByText('Custom Login Screen')).toBeDefined();
   });
+
+  it('renders an error when onFail is called', () => {
+    const oAuthLoginButtonSpy = jest.spyOn(
+      OAuthLoginButtonModule,
+      'OAuthLoginButton',
+    );
+
+    const { findByText } = render(loginScreenInContext);
+
+    expect(oAuthLoginButtonSpy).toHaveBeenCalledTimes(1);
+
+    const onFail = oAuthLoginButtonSpy.mock.calls[0][0].onFail!;
+
+    act(() => {
+      onFail('Fake error');
+    });
+
+    expect(findByText('Authentication Error')).toBeDefined();
+    expect(
+      findByText('We encountered an error trying to log you in.'),
+    ).toBeDefined();
+  });
+
+  const NON_ERRORING_FAILURE_MESSAGES = [
+    'User cancelled flow',
+    "The operation couldn't be completed. (org.openid.appauth.general error -3.)",
+  ];
+
+  test.each(NON_ERRORING_FAILURE_MESSAGES)(
+    'does not render an error when onFail is called with a %p event',
+    (errorMessage) => {
+      const oAuthLoginButtonSpy = jest.spyOn(
+        OAuthLoginButtonModule,
+        'OAuthLoginButton',
+      );
+
+      const { queryByText } = render(loginScreenInContext);
+
+      expect(oAuthLoginButtonSpy).toHaveBeenCalledTimes(1);
+
+      const onFail = oAuthLoginButtonSpy.mock.calls[0][0].onFail!;
+
+      act(() => {
+        onFail(errorMessage);
+      });
+
+      expect(queryByText('Authentication Error')).toBeNull();
+    },
+  );
 });