Are there common testing standards for react.js components?

I'm testing Hero component using jest & enzyme. I thought to my mind that I can do the same thing in the two ways.

For example, I want to get a component's state.

test('Test description', () => {
    const element = shallow(
        <Hero />
    );

    // 1
    expect(element.state()).toBeTruthy();
    // 2
    expect(element.instance().state).toBeTruthy();
});

I have two variants to write this code: using .instance().state or .state(). Probably there are recommendations how to write code like that?