jest mock and RN 0.76.1: TypeError: NativeModule.getConstants is not a function

[andreialecu]

After upgrading to RN 0.76.1, the jest mock seems to fail to import:

    TypeError: NativeModule.getConstants is not a function


    >  9 | import mockSafeAreaContext from 'react-native-safe-area-context/jest/mock';
         | ^


      at Object.getConstants (node_modules/react-native/src/private/specs/modules/NativeDeviceInfo.js:52:32)
      at Object.getConstants (node_modules/react-native/Libraries/Utilities/Dimensions.js:121:33)
      at Object.require (node_modules/react-native/Libraries/Utilities/PixelRatio.js:13:20)
      at Object.require (node_modules/react-native/Libraries/StyleSheet/StyleSheet.js:29:20)
      at Object.require [as StyleSheet] (node_modules/react-native/index.js:306:12)
      at Object.StyleSheet (node_modules/react-native-safe-area-context/lib/commonjs/SafeAreaContext.js:77:29)
      at Object.require (node_modules/react-native-safe-area-context/lib/commonjs/index.js:7:24)
      at Object.requireActual (node_modules/react-native-safe-area-context/jest/mock.tsx:25:32)
      at Object.require (jest.setup.js:9:1)

[paulschreiber]

We're seeing the same thing:
https://github.com/techmatters/terraso-mobile-client/actions/runs/11842140912/job/33000063351

In our case, I don't see react-native-safe-area-context in the stack trace. Filed against react-native-paper: callstack/react-native-paper#4554

[Balthazar33]

I got this for react-native-mmkv-storage.
Sharing the mmkv mock here, in case anyone needs it:

jest.mock('react-native-mmkv-storage', () => {
  return {
    MMKVLoader: jest.fn().mockImplementation(() => {
      return {
        withInstanceID: jest.fn().mockReturnValue({
          initialize: jest.fn().mockResolvedValue({
            setString: jest.fn(),
            getString: jest.fn(),
            removeItem: jest.fn(),
            clearStore: jest.fn(),
            getAllKeys: jest.fn(),
          }),
        }),
        initialize: jest.fn().mockResolvedValue({
          setString: jest.fn(),
          getString: jest.fn(),
          removeItem: jest.fn(),
          clearStore: jest.fn(),
          getAllKeys: jest.fn(),
        }),
      };
    }),
  };
});

Also, I did not add the library's setUp file path in setupFiles in my jest.config file, but appended the package name to transformIgnorePatterns.

I added the mock I've shared above in my jestSetup.js file which has the mocks for the whole app.