react-native-webview/src/__tests__/WebViewShared-test.js

import { Linking } from 'react-native';

import {
  defaultOriginWhitelist,
  createOnShouldStartLoadWithRequest,
} from '../WebViewShared';

Linking.openURL.mockResolvedValue(undefined);
Linking.canOpenURL.mockResolvedValue(true);

// The tests that call createOnShouldStartLoadWithRequest will cause a promise
// to get kicked off (by calling the mocked `Linking.canOpenURL`) that the tests
// _need_ to get run to completion _before_ doing any `expect`ing. The reason
// is: once that promise is resolved another function should get run which will
// call `Linking.openURL`, and we want to test that.
//
// Normally we would probably do something like `await
// createShouldStartLoadWithRequest(...)` in the tests, but that doesn't work
// here because the promise that gets kicked off is not returned (because
// non-test code doesn't need to know about it).
//
// The tests thus need a way to "flush any pending promises" (to make sure
// pending promises run to completion) before doing any `expect`ing. `jest`
// doesn't provide a way to do this out of the box, but we can use this function
// to do it.
//
// See this issue for more discussion: https://github.com/facebook/jest/issues/2157
function flushPromises() {
  return new Promise(resolve => setImmediate(resolve));
}


describe('WebViewShared', () => {
  test('exports defaultOriginWhitelist', () => {
    expect(defaultOriginWhitelist).toMatchSnapshot();
  });

  describe('createOnShouldStartLoadWithRequest', () => {
    const alwaysTrueOnShouldStartLoadWithRequest = (nativeEvent) => {
      return true;
    };

    const alwaysFalseOnShouldStartLoadWithRequest = (nativeEvent) => {
      return false;
    };

    const loadRequest = jest.fn();

    test('loadRequest is called without onShouldStartLoadWithRequest override', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        defaultOriginWhitelist,
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'https://www.example.com/', lockIdentifier: 1 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenCalledWith(true, 'https://www.example.com/', 1);
    });

    test('Linking.openURL is called without onShouldStartLoadWithRequest override', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        defaultOriginWhitelist,
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'invalid://example.com/', lockIdentifier: 2 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledWith('invalid://example.com/');
      expect(loadRequest).toHaveBeenCalledWith(false, 'invalid://example.com/', 2);
    });

    test('loadRequest with true onShouldStartLoadWithRequest override is called', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        defaultOriginWhitelist,
        alwaysTrueOnShouldStartLoadWithRequest,
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'https://www.example.com/', lockIdentifier: 1 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(true, 'https://www.example.com/', 1);
    });

    test('Linking.openURL with true onShouldStartLoadWithRequest override is called for links not passing the whitelist', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        defaultOriginWhitelist,
        alwaysTrueOnShouldStartLoadWithRequest,
      );

      var a = 10;
      onShouldStartLoadWithRequest({ nativeEvent: { url: 'invalid://example.com/', lockIdentifier: 1 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('invalid://example.com/');
      // We don't expect the URL to have been loaded in the WebView because it
      // is not in the origin whitelist
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'invalid://example.com/', 1);
    });

    test('loadRequest with false onShouldStartLoadWithRequest override is called', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        defaultOriginWhitelist,
        alwaysFalseOnShouldStartLoadWithRequest,
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'https://www.example.com/', lockIdentifier: 1 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'https://www.example.com/', 1);
    });

    test('loadRequest with limited whitelist', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
        loadRequest,
        ['https://*'],
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'https://www.example.com/', lockIdentifier: 1 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(true, 'https://www.example.com/', 1);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'http://insecure.com/', lockIdentifier: 2 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('http://insecure.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'http://insecure.com/', 2);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'git+https://insecure.com/', lockIdentifier: 3 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('git+https://insecure.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'git+https://insecure.com/', 3);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'fakehttps://insecure.com/', lockIdentifier: 4 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('fakehttps://insecure.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'fakehttps://insecure.com/', 4);
    });

    test('loadRequest allows for valid URIs', async () => {
      const onShouldStartLoadWithRequest = createOnShouldStartLoadWithRequest(
          loadRequest,
          ['plus+https://*', 'DOT.https://*', 'dash-https://*', '0invalid://*', '+invalid://*'],
      );

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'plus+https://www.example.com/', lockIdentifier: 1 } });
      
      await flushPromises();
      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(true, 'plus+https://www.example.com/', 1);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'DOT.https://www.example.com/', lockIdentifier: 2 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(true, 'DOT.https://www.example.com/', 2);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'dash-https://www.example.com/', lockIdentifier: 3 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenCalledTimes(0);
      expect(loadRequest).toHaveBeenLastCalledWith(true, 'dash-https://www.example.com/', 3);

      onShouldStartLoadWithRequest({ nativeEvent: { url: '0invalid://www.example.com/', lockIdentifier: 4 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('0invalid://www.example.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, '0invalid://www.example.com/', 4);

      onShouldStartLoadWithRequest({ nativeEvent: { url: '+invalid://www.example.com/', lockIdentifier: 5 } });
      
      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('+invalid://www.example.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, '+invalid://www.example.com/', 5);

      onShouldStartLoadWithRequest({ nativeEvent: { url: 'FAKE+plus+https://www.example.com/', lockIdentifier: 6 } });

      await flushPromises();

      expect(Linking.openURL).toHaveBeenLastCalledWith('FAKE+plus+https://www.example.com/');
      expect(loadRequest).toHaveBeenLastCalledWith(false, 'FAKE+plus+https://www.example.com/', 6);
    });
  });
});