ExceptionsManager.handleException is not a function

[eliw00d]

Describe the bug

We recently upgraded to React Native 0.63, Jest 26, and React Native Testing Library 7. When running jest with --runInBand we have noticed the following error randomly in our CI:

/node_modules/react-native/Libraries/LogBox/Data/LogBoxData.js:104
  ExceptionsManager.handleException(error, true);
                    ^
TypeError: ExceptionsManager.handleException is not a function
    at reportLogBoxError (/node_modules/react-native/Libraries/LogBox/Data/LogBoxData.js:108:21)
    at Immediate.<anonymous> (/node_modules/react-native/Libraries/LogBox/Data/LogBoxData.js:217:7)
    at processImmediate (internal/timers.js:456:21)

I noticed a similar error in the previous project: testing-library/native-testing-library#132

Any thoughts?

Expected behavior

No errors.

Versions

❯ npx envinfo --npmPackages react,react-native,react-test-renderer,@testing-library/react-native

  npmPackages:
    @testing-library/react-native: 7.0.2 => 7.0.2 
    react: 16.13.1 => 16.13.1 
    react-native: 0.63.2 => 0.63.2 
    react-test-renderer: 16.13.1 => 16.13.1 

[thymikee]

This library has nothing to do with LogBox, nor ExceptionsManager. Make sure to use "react-native" Jest preset and mock the native module if necessary. Looks like ExceptionsManager is already mocked, but handleException is not there: https://github.com/facebook/react-native/blob/master/jest/setup.js#L42

[lukewlms]

@thymikee Trying to deal with this too (discussing on RN GH) - can you help me understand why some parts of RN are mocked by RNTL but not others? E.g. LogBox is but not ExceptionManager. Is that b/c LogBox is a Component?

RNTL has this:

// Mock LogBox
jest.mock('react-native/Libraries/LogBox/LogBox');

But not something like this:

jest.mock("react-native/Libraries/Core/ExceptionsManager", () => ({
  handleException: (...args: any[]) => console.log(args),
}));

It also seems odd that despite LogBox being apparently mocked by RNTL, these errors still appear... perhaps because LogBox/LogBox is mocked but LogBox/Data is not. Not sure if the RNTL team would consider that in scope or not.

ReferenceError: You are trying to `import` a file after the Jest environment has been torn down.

      at reportLogBoxError (node_modules/react-native/Libraries/LogBox/Data/LogBoxData.js:85:27)
      at Immediate._onImmediate (node_modules/react-native/Libraries/LogBox/Data/LogBoxData.js:202:7)

FYI we can get around this issue ok by moving this line to the top of LogBoxData.js in node_modules/react-native:

const ExceptionsManager = require('../../Core/ExceptionsManager');

And adding this to the mocks in jest/setup.js:

  .mock("../Libraries/Core/ExceptionsManager", () => {
    return {
      handleException: (...args) => {
        return;
      },
    };
  })

[thymikee]

RNTL provides no mocks on its own, where did you get that information from? It's "react-native" Jest preset that ships with React Native that handles mocking for Jest. If something is not there, while it should, send a PR to the core RN repo :)

[lukewlms]

Ah somehow I hallucinated that 🙂 thanks for the info!!

[gustavommarini]

I tried to avoid edit the LogBoxData.js and this solved my problem. :)