Jest : Mock import of JSON file

You can either use moduleNameMapper in your jest settings to point the import to an mocked json file.

{
  "moduleNameMapper": {
    "setting.json": "<rootDir>/__mocks__/setting.json"
  }
}

Or you can use jest.mock inside your test to mock the file directly, note that you have to add the { virtual: true } parameter.

jest.mock('path/to/setting.json', ()=>({
  settings: 'someSetting'
}), { virtual: true })

For those looking to mock JSON in the form of an Array, just return an array from the callback.

jest.mock('./data.json', () => ([1, 2, 3]));

You can return other valid JSON types as well: Object, String, Number, Boolean, or Null.

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