export default function (point) { checkCoord(point.x); checkCoord(point.y); } function checkCoord(num) { if (typeof Number.isFinite === 'function') { if (Number.isFinite(num)) { return; } throw new TypeError('coordinates must be finite numbers'); } if (typeof num !== 'number' || num !== num || !isFinite(num)) { throw new TypeError('coordinates must be finite numbers'); } }