wip live apollo link

LiveLink.js

// @flow

import { visit, Kind } from 'graphql/language'
import { ApolloLink, Observable } from 'apollo-link'
import traverse from 'traverse'
import createLiveSubscription from './createLiveSubscription'
import debounce from 'lodash/debounce'

export function parseLiveDirectives(query) {
  return visit(query, {
    [Kind.FIELD]: {
      enter(node, key, parent) {
        if ((node.directives || []).find(d => d.name.value === 'live')) {
          parent.push({
            kind: 'Field',
            name: {
              kind: 'Name',
              value: `${node.name.value}_liveKeys`
            },
            arguments: node.arguments,
            directives: [],
            selectionSet: null
          })
        }
      }
    },
    [Kind.DIRECTIVE]: {
      leave(node) {
        if (node.name.value === 'live') {
          return null
        }
      }
    }
  })
}


export default class LiveLink extends ApolloLink {
  request(operation, forward) {
    operation.query = parseLiveDirectives(operation.query)
    const originalContext = operation.getContext()

    return new Observable(observer => {
      const liveUpdates = createLiveSubscription(debounce(() => {
        console.log(`@live reload ${operation.operationName}`)
        operation.setContext(originalContext)
        this.subscription.unsubscribe()
        this.subscription = forward(operation).subscribe(subscriber)
      }, 100))

      const subscriber = {
        next: data => {
          const liveKeys = []
          traverse(data).forEach(function (value) {
            if (this.key && this.key.endsWith('_liveKeys')) {
              liveKeys.push(...value)
            }
          })
          console.log('data', operation.operationName, data)
          console.log('settingLiveKeys', liveKeys)
          liveUpdates.setLiveKeys(liveKeys)

          observer.next(data);
        },
        error: error => observer.error(error),
      }

      this.subscription = forward(operation).subscribe(subscriber)

      return () => {
        console.log('CLOSE QUERY', operation.operationName)
        liveUpdates.unsubscribe()
        this.subscription.unsubscribe()
      }
    })
  }
}