useful error when switching numColumns on the fly

Reviewed By: blairvanderhoof, bvaughn Differential Revision: D4742842 fbshipit-source-id: a11a088194ead02cc11eb6ccd9ce6d6f75ead3a3
facebook · Mar 22, 2017 · 46d6766 · 46d6766
1 parent 1531f5f
commit 46d6766
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/Libraries/CustomComponents/Lists/FlatList.js b/Libraries/CustomComponents/Lists/FlatList.js
@@ -242,6 +242,11 @@ class FlatList<ItemT> extends React.PureComponent<DefaultProps, Props<ItemT>, vo
   }
 
   componentWillReceiveProps(nextProps: Props<ItemT>) {
+    invariant(
+      nextProps.numColumns === this.props.numColumns,
+      'Changing numColumns on the fly is not supported. Change the key prop on FlatList when ' +
+      'changing the number of columns to force a fresh render of the component.'
+    );
     this._checkProps(nextProps);
   }