Check if _document.js returns a react element before using (#2013)

* Check if _document.js returns a react element before using * Use capital letter R in 'React'
vercel · May 19, 2017 · d36118a · d36118a
1 parent 23a4809
commit d36118a
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/server/render.js b/server/render.js
@@ -90,6 +90,7 @@ async function doRender (req, res, pathname, query, {
 
   if (res.finished) return
 
+  if (!Document.prototype || !Document.prototype.isReactComponent) throw new Error('_document.js is not exporting a React element')
   const doc = createElement(Document, {
     __NEXT_DATA__: {
       props,