Jest - Mock useMutation

index.test.tsx

// Method 1
jest.mock('react-query', () => ({
  useMutation: jest.fn()
}));

const mockMutationFn = jest.fn().mockRejectedValue(new Error('Mutation failed'));
(useMutation as jest.Mock).mockReturnValue([mockMutationFn, {}]);

expect(actionCreatorsModal.setIsError).toHaveBeenCalledWith(true, expect.any(Object));

// Method 2
jest.mock('react-query', () => ({
  useMutation: jest.fn()
}));

const mockMutationFn = { mutate: () => mockedMutate() };
(useMutation as jest.Mock).mockReturnValue(mockMutationFn);

expect(mockedMutate).toHaveBeenCalled();