GraphQL Tx over Websocket SDK

index.js

const WebSocket = require('ws')
const WebSocketAsPromised = require('websocket-as-promised')

// SDK Code
const socketFactory = (url) =>
  new WebSocket(url, 'graphql-tx', {
    headers: {
      'X-Hasura-Tx-Isolation': 'serializable',
    },
  })

const socket = new WebSocketAsPromised('ws://localhost:8080/v1/graphql', {
  createWebSocket: (url) => socketFactory(url),
  extractMessageData: (event) => event,
  packMessage: (data) => data,
  unpackMessage: (data) => JSON.parse(data as string),
  attachRequestId: (data, requestId) => data,
  extractRequestId: (data) => data && data.request_id,
})

const txns = {
  init: JSON.stringify({
    type: 'init',
    payload: {
      isolation: 'serializable',
    },
  }),
  abort: JSON.stringify({
    type: 'abort',
  }),
  commit: JSON.stringify({
    type: 'commit',
  }),
  sendQuery: (query) =>
    JSON.stringify({
      type: 'execute',
      payload: {
        query: {
          query: query,
        },
      },
    }),
}

socket.onResponse.addListener((data, requestId) => {
  console.log('response data:', data)
  const reqPromise = socket._requests._items.get('req')
  reqPromise.resolve(data)
})

socket.onMessage.addListener((data) => console.log('data:', data))
socket.onSend.addListener((...data) => console.log('sent', data))

const transaction = (query) => {
  let result
  return socket
    .open()
    .then(() => socket.send(txns.init))
    .then(() =>
      socket.sendRequest(txns.sendQuery(query), { requestId: 'req' })
    )
    .then((response) => {
      result = response
      socket.send(txns.commit)
    })
    .then(() => {
      console.log('Committed transaction, got result:', result)
      return result
    })
    .catch((err) => {
      socket.send(txns.abort)
      console.log('Error:', err)
    })
}

// Demo code
const getUserQuery = 'query q { users { id name} }'

transaction(getUserQuery).then((res) => {
  console.log('Transaction finished with response', res)
})