Set contentWindow default ourselves to avoid Jest serialization

Jest serializes all props in snapshots. Window is a huge object, so when Jest tries to serialize it, it typically throws `RangeError: Invalid string length` because the process runs out of memory. This switches from using defaultProps to setting the default ourselves, so in the test environment there won't be a prop value to serialize.

Author: cameronmcefee

src/SortableContainer/index.js

@@ -44,7 +44,6 @@ export default function sortableContainer(WrappedComponent, config = {withRef: f
       distance: 0,
       useWindowAsScrollContainer: false,
       hideSortableGhost: true,
-      contentWindow: typeof window !== 'undefined' ? window : null,
       shouldCancelStart: function(e) {
         // Cancel sorting if the event target is an `input`, `textarea`, `select` or `option`
         const disabledElements = ['input', 'textarea', 'select', 'option', 'button'];
@@ -100,11 +99,17 @@ export default function sortableContainer(WrappedComponent, config = {withRef: f
 
     componentDidMount() {
       const {
-        contentWindow,
         getContainer,
         useWindowAsScrollContainer,
       } = this.props;
 
+      /*
+       *  Set our own default rather than using defaultProps because Jest
+       *  snapshots will serialize window, causing a RangeError
+       *  https://github.com/clauderic/react-sortable-hoc/issues/249
+       */
+      const contentWindow = this.props.contentWindow || window;
+
       this.container = typeof getContainer === 'function'
         ? getContainer(this.getWrappedInstance())
         : findDOMNode(this);