function reactRouter(router) {
  return (reducer, initialState) => next => {
    const baseStore = next(reducer, initialState);

    function storeIsInSyncWithRouter() {
      //... blah blah implementation details
    }

    // Apply router middleware which intercepts TRANSITION_TO actions
    const wrappedDispatch = routerMiddleware(router)()(baseStore.dispatch);

    const store = {
      ...baseStore,
      dispatch: (action) => {
        wrappedDispatch(action);

        // After dispatching, check if store state is out of sync with router
        if (!storeIsInSyncWithRouter()) {
          const { pathname, query, state } = baseStore.getState().router;
          // Trigger transition in response to external state change
          // E.g. Redux Devtools time travel
          router.transitionTo(pathname, query, state);
        }

        return action;
      }
    };

    // Need some way to subscribe to transitions
    // Different from History.addChangeListener because transitions may be
    // aborted, redirected, async, etc.
    router.subscribe((location, params, components) => {
      // Triggers LOCATION_DID_CHANGE actions
      // (probably should rename this to DID_TRANSITION_TO for clarity)
      if (!storeIsInSyncWithRouter()) {}
        baseStore.dispatch(locationDidChange(location, params));
      }
    });

    return store;
  };
}

// Compose with other higher-order stores
const store = compose(
  applyMiddleware(m1, m2, m3)
  reactRouter(router),
  devTools,
  createStore
)(reducer, initialState);