Cannot read property 'decelerationRate' of undefined

[shilman]

Issue by xareelee
Thursday Mar 16, 2017 at 09:26 GMT
Originally opened as storybook-eol/storyshots#86

---

When I use jest/storyshots to run the snapshot tests. It shows an abnormal error (TypeError: Cannot read property 'decelerationRate' of undefined ):

 FAIL  storybook/Storyshots.test.js
  ● Storyshots › [Page] CountryPolicy › entry

    TypeError: Cannot read property 'decelerationRate' of undefined
      
      at Object.<anonymous> (node_modules/react-native/Libraries/Components/WebView/WebView.ios.js:555:3254)
      at Object.get WebView [as WebView] (node_modules/react-native/Libraries/react-native/react-native.js:68:22)
      at CountryPolicy (src/ui/CountryPolicy/CountryPolicy.js:11:43)
      at node_modules/react-test-renderer/lib/ReactCompositeComponent.js:306:16
      at measureLifeCyclePerf (node_modules/react-test-renderer/lib/ReactCompositeComponent.js:75:12)
      at ReactCompositeComponentWrapper._constructComponentWithoutOwner (node_modules/react-test-renderer/lib/ReactCompositeComponent.js:305:14)
      at ReactCompositeComponentWrapper._constructComponent (node_modules/react-test-renderer/lib/ReactCompositeComponent.js:280:21)

Source code:

// CountryPolicy.jsx
const CountryPolicy = () => (
  <WebView
    style={styles.wrapper}
    source={{ uri: policyUrl }}
  />
) 

Story:

// CountryPolicy.stories.js
storiesOf('[Page] CountryPolicy', module)
  .add('entry', () => (
    <CountryPolicy />
  ));

The app displays normally. It seems something wrong when testing a DOM containing a WebView.

[shilman]

Comment by jrdrg
Friday Mar 17, 2017 at 12:45 GMT

---

Possibly the same issue referenced in storybook-eol/storyshots#76?

[tmeasday]

@xareelee - did you have any luck with this one? It sounds like an issue with React Native's implementation of the <WebView/> component which is still unresolved: facebook/react-native#12440.

Is there anything we can do to avoid the problem? It sounds like the issue is with refs inside the WebView so I don't think the issue @shilman mentioned above will help (although I'm not sure).

I'll close this for now, but @-me or comment on this issue if there is something we could do to work around it.

[xareelee]

@tmeasday

Currently, I fixed this by adding jest.unmock('ScrollView') in the .fest_config.js which is mentioned on facebook/react-native#12440 (comment).

It seems that React Native team should fix the issue.

[tmeasday]

@xareelee OK, thanks for posting that, hopefully it will help anyone else who runs into this problem!