Support react test renderer

[bseber]

refs #163

• replaced findDOMNode with ref since findDOMNode is deprecated and should not be used. see official react docs: https://facebook.github.io/react/docs/react-dom.html#finddomnode

please note: only tested with my project at work! I'm not sure if this is stable and backwards compatible.

currently I have mocked the react-list in my project to just call the itemsRenderer to render all list items:

import React from 'react';

const ref = () => {}; // NOSONAR

export default class ReactListMock extends React.Component {
    getVisibleRange () {
        return [0, 42];
    }

    render () {
        const {
            items,
            itemsRenderer,
            itemRenderer,
        } = this.props;
        const itemElements = items.map ((item, index) => itemRenderer (index, index));
        return itemsRenderer (itemElements, ref);
    }
}

and I have unit tests to check click behaviour which did not pass anymore since not all list items are rendered by default react-list settings.

it ('calls "onBestellungClick" when a list item is clicked', () => {
    const root = document.createElement ('div');
    const props = setup ();

    renderIntoDocumentWithIntl (
        <BestellungHistoryList {...props} />,
        root
    );

    const listitems = root.querySelectorAll ('li');
    ReactTestUtils.Simulate.click (listitems[1], {});

    expect (props.onBestellungClick).toHaveBeenCalledWith (props.bestellungen[1]);
});

adding minSize property solved this:

<ReactList
    type="uniform"
    useStaticSize
    items={bestellungen}
    length={bestellungen.length}
+    minSize={10}
    itemsRenderer={(items, ref) => renderList (items, ref)}
    itemRenderer={(index) => renderItem (bestellungen[index], onBestellungClick)}
/>

[DrGor]

ReactDOM.findDOMNode is not deprecated. It works in React 16 without warnings.
This being said, I totally agree that you should dodge using findDOMNode if it's possible.