[Solved]-ReactJS/Jest: How to test/mock a function, which is passed to component-Reactjs

Without actually testing it, I believe this is what you need:

it('handleChange() should set state.term', () => {
  const togglePosition = jest.fn();
  const event = { target: { value: 'test' } };
  const wrapper = shallow(<Child togglePosition={togglePosition} />);

  wrapper.find('#target-input').simulate('change', event);
  const state = wrapper.instance().state;
  expect(state).toEqual({ loading: 'loading', term: 'test' });
  expect(togglePosition).toHaveBeenCalledWith('test');
})

Mock the passed function: const togglePosition = jest.fn();, and test the condition/response: expect(togglePosition).toHaveBeenCalledWith('test');.