import {split, createStore, createEvent, createApi} from 'effector'

​

const textContent = createStore([])

​

const messageReceived = createEvent()

​

split({

  source: messageReceived,

  match: {

    text: msg => msg.type === 'text',

    audio: msg => msg.type === 'audio',

  },

  cases: createApi(textContent, {

    text: (list, {value}) => [...list, value],

    audio: (list, {duration}) => [...list, `audio ${duration} ms`],

    __: list => [...list, 'unknown message'],

  }),

})

​

textContent.watch(messages => {

  console.log(messages)

})

​

messageReceived({

  type: 'text',

  value: 'Hello',

})

// => ['Hello']

messageReceived({

  type: 'image',

  imageUrl: '...',

})

// => ['Hello', 'unknown message']

messageReceived({

  type: 'audio',

  duration: 500,

})

// => ['Hello', 'unknown message', 'audio 500 ms']