Fix prop-types to correcly assign props to components (fixes #991)

Author: yannickcr

lib/rules/prop-types.js

@@ -586,7 +586,7 @@ module.exports = {
       }
 
       var component = components.get(utils.getParentComponent());
-      var usedPropTypes = component && component.usedPropTypes || [];
+      var usedPropTypes = (component && component.usedPropTypes || []).slice();
 
       switch (type) {
         case 'direct':

tests/lib/rules/prop-types.js

@@ -1415,6 +1415,19 @@ ruleTester.run('prop-types', rule, {
           jsx: true
         }
       }
+    }, {
+      code: [
+        'export class Example extends Component {',
+        '  static propTypes = {',
+        '    onDelete: React.PropTypes.func.isRequired',
+        '  }',
+        '  handleDeleteConfirm = () => {',
+        '    this.props.onDelete();',
+        '  };',
+        '  handleSubmit = async ({certificate, key}) => {};',
+        '}'
+      ].join('\n'),
+      parser: 'babel-eslint'
     }
   ],