server.js

// RENDER PAGE
server.all('*', (req, res) => {
  const { store } = req;

  match({ routes, location: req.url }, (error, redirectLocation, renderProps) => {
    if (redirectLocation) {
      res.redirect(301, redirectLocation.pathname + redirectLocation.search);
    } else if (error) {
      res.status(500).send(error.message);
    } else if (!renderProps) {
      res.status(404).send('Not found');
    } else {
      const { location, params } = renderProps;
      const { dispatch, getState } = store;

      const dataFetchingRequirements = renderProps.components
        .map(component => component.WrappedComponent && component.WrappedComponent.fetchData)
        .filter(fetchData => fetchData !== undefined)
        .map(fetchData => fetchData({ location, params, dispatch }));

      Promise.all(dataFetchingRequirements)
        .catch(() => {}) // Ignore errors from data fetching
        .then(() => {
          const reduxState = getState();
          const markup = renderToString(
            <Provider store={store}>
              <RouterContext {...renderProps} />
            </Provider>
          );

          res.send(renderPage(markup, reduxState));
        });
    }
  });
});