react-selectable/src/getBoundsForNode.js

Allows individual or group selection of items using the mouse.

/**
 * Given a node, get everything needed to calculate its boundaries
 * @param  {HTMLElement} node 
 * @return {Object}
 */
export default node => {
	const rect = node.getBoundingClientRect();
	
	return {
		top: rect.top+document.body.scrollTop,
		left: rect.left+document.body.scrollLeft,
		offsetWidth: node.offsetWidth,
		offsetHeight: node.offsetHeight
	};
};