TypeError: batch is not a function in Jest

    TypeError: batch is not a function
      at Object.batch [as notify] (node_modules/react-redux/lib/utils/Subscription.js:29:7)
      at Subscription.notify [as notifyNestedSubs] (node_modules/react-redux/lib/utils/Subscription.js:71:20)
      at notifyNestedSubs (node_modules/react-redux/lib/components/connectAdvanced.js:272:13)
      at checkForUpdates (node_modules/react-redux/lib/components/connectAdvanced.js:296:9)
      at create (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:10867:26)
      at commitHookEffectList (node_modules/react-test-renderer/cjs/react-test-renderer.develo

Versions

    "react": "^16.9.0",
    "react-native": "0.60.5",
    "react-redux": "7.0.0",
    "redux": "^4.0.0",
    "redux-persist": "^5.10.0",

Once I updated to 7.0, this problem appears in all test cases using react-redux. When I go into node_modules/react-redux/lib/utils/Subscription.js and change line

var batch = (0, _batch.getBatch)(); to var batch = (0, _batch.getBatch);

it works fine

[alnorris]

Was able to temporarily get around the issue with this.

jest.mock('../../node_modules/react-redux/lib/utils/batch.js', () => ({
  setBatch: jest.fn(),
  getBatch: () => fn => fn()
}))

[shirakaba]

In case it helps anyone, here is how I’ve attempted to implement unstable_batchedUpdates for my React custom renderer without creating a dependency upon React DOM or React Native. It’s undocumented, so I have no idea.

My app is now freezing at run-time post state update, rather than crashing at startup, so I think it’s at least a step in the right direction. And the latter part about freezing may not even be related.

EDIT: My methodology seems to be exactly the same as that used by react-three, so I can at least have some confidence in advising it.