In case ESLint is configured to not allow using the underscore dangle, wrap it like so:

+ /* eslint-disable no-underscore-dangle */
  const store = createStore(
   reducer, /* preloadedState, */
   window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()
  );
+ /* eslint-enable */

const composeEnhancers = typeof window === 'object' && window.REDUX_DEVTOOLS_EXTENSION_COMPOSE ?
window.REDUX_DEVTOOLS_EXTENSION_COMPOSE({ // Specify extension’s options like name, actionsBlacklist, actionsCreators, serialize... }) : compose;

const enhancer = composeEnhancers( applyMiddleware(...middleware), // other store enhancers if any ); const store = createStore(reducer, enhancer);

In case you don't include other enhancers and middlewares, just use `devToolsEnhancer`:
```js
import { createStore } from 'redux';
import { devToolsEnhancer } from 'redux-devtools-extension';

const store = createStore(reducer, /* preloadedState, */ devToolsEnhancer(
  // Specify name here, actionsBlacklist, actionsCreators and other options if needed
));

If you want to restrict it there, use redux-devtools-extension/logOnlyInProduction:

import { createStore } from 'redux';
import { devToolsEnhancer } from 'redux-devtools-extension/logOnlyInProduction';

const store = createStore(reducer, /* preloadedState, */ devToolsEnhancer(
  // options like actionSanitizer, stateSanitizer
));

or with middlewares and enhancers:

import { createStore, applyMiddleware } from 'redux';
import { composeWithDevTools } from 'redux-devtools-extension/logOnlyInProduction';

const composeEnhancers = composeWithDevTools({
  // options like actionSanitizer, stateSanitizer
});
const store = createStore(reducer, /* preloadedState, */ composeEnhancers(
  applyMiddleware(...middleware),
  // other store enhancers if any
));

If you're already checking process.env.NODE_ENV when creating the store, include redux-devtools-extension/logOnly for production environment.

If you don’t want to allow the extension in production, just use redux-devtools-extension/developmentOnly.