export default function(items, props) {
  const { columnWidth, itemHeight = 150, columns,
    gutterWidth, gutterHeight } = props;

  const positions = items.map((itemProps, i) => {
    const column = i % columns;
    const row = Math.floor(i / columns);

    const x = (column * columnWidth) + (column * gutterWidth);
    const y = (row * itemHeight) + (row * gutterHeight);

    return [x, y];
  });

  const gridWidth = (columns * columnWidth) + ((columns - 1) * gutterWidth);
  const gridHeight = (Math.ceil(items.length / columns) *
    (itemHeight + gutterHeight)) - gutterHeight;

  return { positions, gridWidth, gridHeight };
}

@@ -1,8 +1,9 @@
+%0A
 export d

add prop-types package