Fix tests

Author: VeraZab

src/components/containers/Section.js

@@ -53,6 +53,7 @@ class Section extends Component {
       if (child.plotProps) {
         plotProps = child.plotProps;
       } else if (
+        fullContainer &&
         fullContainer.type === 'scatter' &&
         !fullContainer.opacity &&
         child.props.attr === 'opacity'

src/components/containers/__tests__/Section-test.js

@@ -55,7 +55,7 @@ describe('Section', () => {
       </TestEditor>
     ).find('[name="test-section"]');
 
-    expect(wrapper.children().length).toBe(1);
+    expect(wrapper.children().length).toBe(2);
     expect(wrapper.find('.extra').text()).toBe('special extra');
   });