const createStore = require('redux').createStore

function counter(
    state = { location: 'shanghai', driveTime: 36000, driveDistance: '10000' },
    action
) {
    switch (action.type) {
        case 'pushLocation':
            return state.location
        case 'pushDriveTime':
            return state.driveTime
        case 'pushDriveDistance':
            return state.driveDistance
        default:
            return state
    }
}

let store = createStore(counter)

store.subscribe(() => console.log(store.getState()))
store.dispatch({ type: 'pushDriveDistance' })