SyntaxError: Unexpected token export using jest

Current behavior

/@react-native-community/async-storage/lib/index.js:1
    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export default from './AsyncStorage';

 SyntaxError: Unexpected token export

    > 1 | import AsyncStorage  from "@react-native-community/async-storage"
        | ^
      2 | 
      3 | /**
      4 |  * Loads a string from storage.

Repro steps

import @react-native-community/async-storage and test with jest.

Environment

• Async Storage version: 1.2.1
• React-Native version: 0.57.7
• Platform tested: iOS / Android
• Jest version: 24.0.11
• Logs/Error that are relevant: see above

[krizzu]

Hey @loic-lopez

Async Storage is not being transformed by Jest, so in your jest.config.js or jest entry in package.json, add:

"transformIgnorePatterns": ["/node_modules/@react-native-community/async-storage/(?!(lib))"]

[vgm8]

Sure @Krizzu! As you said in your comment I’ve created __mocks__/@react-native-community/async-storage/index.js

let cache = {};
export default {
  setItem: (key, value) => {
    return new Promise((resolve, reject) => {
      return (typeof key !== 'string' || typeof value !== 'string')
        ? reject(new Error('key and value must be string'))
        : resolve(cache[key] = value);
    });
  },
  getItem: (key, value) => {
    return new Promise((resolve) => {
      return cache.hasOwnProperty(key)
        ? resolve(cache[key])
        : resolve(null);
    });
  },
  removeItem: (key) => {
    return new Promise((resolve, reject) => {
      return cache.hasOwnProperty(key)
        ? resolve(delete cache[key])
        : reject('No such key!');
    });
  },
  clear: (key) => {
    return new Promise((resolve, reject) => resolve(cache = {}));
  },

  getAllKeys: (key) => {
    return new Promise((resolve, reject) => resolve(Object.keys(cache)));
  },
}

An then in my tests I just import and mock @react-native-community/async-storage like this:

import AsyncStorage from '@react-native-community/async-storage';
jest.mock('@react-native-community/async-storage');