redux-first-router-confirm-leave.js

const history = createHistory({
  getUserConfirmation(message, callback) {
    confirmationDialog(message, (res) => {
      shouldChange = !!res
      callback(res)
    })
  }
})

history.block((location, action) => {
  const state = selectLocationState(getState())
  let action = pathToAction(location.pathname, routesMap)
  const route = routesMap[action.type]

  if (route) {
    action = middlewareCreateAction(
      action,
      routesMap,
      prevLocation,
      history,
      notFoundPath,
      querySerializer
    )

    const nextState = reducer(state, action)
    const res = confirmLeave(state, nextState)

    if (res) {
      shouldChange = false
    }

    return res
  }
})

function confirmLeave(current, next) {
  if (current.type === 'LIST' && next.type === 'HOME') {
    return 'are u sure u wanna leave?'
  }
}