[Tests] jsx-key: add some debugging info

Author: ljharb

Diff for: lib/rules/jsx-key.js

@@ -95,7 +95,7 @@ module.exports = {
         if (node.alternate) {
           getReturnStatements(node.alternate, returnStatements);
         }
-      } else if (node.body) {
+      } else if (Array.isArray(node.body)) {
         node.body.forEach((item) => {
           if (item.type === 'IfStatement') {
             getReturnStatements(item, returnStatements);
@@ -105,6 +105,8 @@ module.exports = {
             returnStatements.push(item);
           }
         });
+      } else if (node.body) {
+        throw new TypeError(`jsx-key: non-array truthy node.body found: ${JSON.stringify(node.body)}`);
       }
 
       return returnStatements;