Use proxyquire to deal with platform specific extensions when writing test for React Native code

index.js

import TheModule from 'platform-specific-module';

export default class ComponentUnderTest extends Component {
  render() {
    return (
      <TheModule />
    )
  }
}

index.spec.js

import proxyquire from 'proxyquire';
import platformSpecificModule from 'platform-specific-module/index.ios'; // or whichever version you prefer

const SubjectUnderTest = proxyquire.noCallThru().load('./index', {
  'platform-specific-module': {
    'TheModule': platformSpecificModule
  }
}).default

This only works cause your imports are converted to commonJS requires BTW.
If/once node.js supports import natively then proxyquire won't work this way anymore .. just a heads up and maybe you should stick with require anyhow for now ;)