index.js

import React from "react";
import ReactDOM from "react-dom";
import { Provider } from "react-redux";
import { ConnectedRouter } from "connected-react-router/immutable";
import createHistory from "history/createBrowserHistory";

import App from "containers/App";
import configureStore from "./configureStore";
import registerServiceWorker from "./registerServiceWorker";

import {
  CssBaseline,
  MuiThemeProvider,
  createMuiTheme
} from "@material-ui/core";

// Create redux store with history
const initialState = {};
const history = createHistory({});
const store = configureStore(initialState, history);

const theme = createMuiTheme({
  palette: {
    primary: {
      main: "#1976d2"
    },
    secondary: {
      main: "#c2185b"
    }
  }
});

ReactDOM.render(
  <Provider store={store}>
    <ConnectedRouter history={history}>
      <CssBaseline>
        <MuiThemeProvider theme={theme}>
          <App />
        </MuiThemeProvider>
      </CssBaseline>
    </ConnectedRouter>
  </Provider>,
  document.getElementById("root")
);

registerServiceWorker();

if (module.hot) {
  module.hot.accept("containers/App", () => {
    ReactDOM.render(
      <Provider store={store}>
        <ConnectedRouter history={history}>
          <CssBaseline>
            <MuiThemeProvider theme={theme}>
              <App />
            </MuiThemeProvider>
          </CssBaseline>
        </ConnectedRouter>
      </Provider>,
      document.getElementById("root")
    );
  });
}