Fix crash with empty destructuring (fixes #251)

Author: yannickcr

lib/rules/prop-types.js

@@ -364,6 +364,7 @@ module.exports = function(context) {
         } else if (
           node.parent.id &&
           node.parent.id.properties &&
+          node.parent.id.properties.length &&
           getKeyValue(node.parent.id.properties[0])
         ) {
           type = 'destructuring';

tests/lib/rules/prop-types.js

@@ -756,6 +756,21 @@ ruleTester.run('prop-types', rule, {
       ecmaFeatures: {
         jsx: true
       }
+    }, {
+      code: [
+        'class Hello extends React.Component {',
+        '  render() {',
+        '    const {} = this.props;',
+        '    return <div>Hello</div>;',
+        '  }',
+        '}'
+      ].join('\n'),
+      env: {
+        es6: true
+      },
+      ecmaFeatures: {
+        jsx: true
+      }
     }
   ],