We purge it [here](https://github.com/facebook/react/blob/b11540ccb2321aeb7259fcf0b3a38aeeea35231d/src/isomorphic/ReactDebugTool.js#L88-L89) but this code doesn’t run because of the [early exit](https://github.com/facebook/react/blob/b11540ccb2321aeb7259fcf0b3a38aeeea35231d/src/isomorphic/ReactDebugTool.js#L53-L57).

Need to fix this and add a test case to make sure we don’t regress on it.

type: 'update attribute',
          payload: { 'data-y': 43 },
        }]);
      });
    });
    describe('attribute on a web component', () => {
      it('gets recorded during mount', () => {
        var node = document.createElement('div');
        ReactDOM.render(<my-component className="rad" tabIndex={42} />, node);
        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
        if (ReactDOMFeatureFlags.useCreateElement) {
          assertHistoryMatches([{
            instanceID: inst._debugID,
            type: 'update attribute',
            payload: { className: 'rad' },
          }, {
            instanceID: inst._debugID,
            type: 'update attribute',
            payload: { tabIndex: 42 },
          }, {
            instanceID: inst._debugID,
            type: 'mount',
            payload: 'MY-COMPONENT',
          }]);
        } else {
          assertHistoryMatches([{
            instanceID: inst._debugID,
            type: 'mount',
            payload: '<my-component className="rad" tabIndex="42" ' +
            'data-reactroot="" data-reactid="1"></my-component>',