How can I test a modal inside of a React Portal using React Testing Library?

I'm trying to test my Modal component with React Testing Library. The Modal is rendered inside of a React Portal. Now when I try to match my Modal with a snapshot the snapshot gets rendered as an empty div.

test('The component should render in body when open', () => {
    const {container} = render(
        <Modal>
            <div>My dialog content</div>
        </Modal>
    );

    expect(container).toMatchSnapshot();
});

The snapshot I get looks like this:

exports[`The component should render in body when open 1`] = `<div />`;

I've seen a few workarounds for instance passing {container: document.body} as a second argument to the render() function. But nothing really worked.

Also I cannot query for any elements via container. It always returns null.

const dialog = container.querySelector(".modal");
console.log(dialog); // null

I eventually made it work by snapshotting baseElement instead of container Both are returned properties by the render() function.

test('The component should render in body when open', () => {
    const {baseElement} = render(
        <Modal>
            <div>My dialog content</div>
        </Modal>
    );

    expect(baseElement).toMatchSnapshot();
});