apollo-client-config.js

import pkg from '../../../package'
import _ from 'lodash'
import {
  ApolloClient,
  from,
  HttpLink,
  InMemoryCache,
  split,
} from '@apollo/client'
import { onError } from '@apollo/link-error'
import { WebSocketLink } from '@apollo/link-ws'
import { setContext } from '@apollo/link-context'
import { getMainDefinition } from '@apollo/client/utilities'
import { env } from '../../../constants/environment'
import { getAuthenticationInformation } from '../../authentication'

/**
 * Apollo cache instance
 */
export const cache = new InMemoryCache({
  possibleTypes: {},
  typePolicies: {
    Company: {
      keyFields: ['symbol'],
    },
    Quote: {
      keyFields: ['symbol'],
    },
  },
})

/**
 * HTTP Link
 */
const httpLink = new HttpLink({
  uri: `${env.apiHost}/meatball`,
})

/**
 * WebSocket link for subscriptions
 */
const wsLink = new WebSocketLink({
  uri: `${env.wsHost}/meatball`,
  options: {
    reconnect: true,
    connectionParams: async () => {
      const { token } = await getAuthenticationInformation()
      return {
        authorization: `Bearer ${token}`,
      }
    },
  },
})

/**
 * Sets auth token on an individual request
 */
const authorizationLink = setContext(async (_request, _previousContext) => {
  const { token } = await getAuthenticationInformation()
  const headers = {
    authorization: `Bearer ${token}`,
  }

  return { headers }
})

/**
 * Single place to handle errors
 */
const handleErrorLink = onError(
  ({ forward, graphQLErrors, operation, response }) => {
    /**
     * Do error handling here
     */
    return forward(operation)
  }
)

const remoteDataLink = split(
  ({ query }) => {
    const definition = getMainDefinition(query)
    return (
      definition.kind === 'OperationDefinition' &&
      definition.operation === 'subscription'
    )
  },
  wsLink,
  httpLink
)

/**
 * Apollo Client instance
 */
export const client = new ApolloClient({
  cache,
  link: from([authorizationLink, handleErrorLink, remoteDataLink]),
  name: _.get(pkg, ['name']),
  version: _.get(pkg, ['version']),
})