A better apollo integration

[Sytten]

Now I am not sure where to post that since there doesn't seem to be big community around the project, but I wrote a better integration for apollo:

import { ApolloServerPlugin } from 'apollo-server-plugin-base'
import { RewriteHandler, Rewriter } from 'graphql-query-rewriter'

import { Context } from '~/context'

// An optimization that could be done is avoiding a query parsing
// and reprinting in the input. Not sure how to do this.
export const GraphQLQueryRewriter = (
  rewriters: Rewriter[]
): ApolloServerPlugin<Context> => ({
  requestDidStart(reqCtx) {
    const { request } = reqCtx

    const handler = new RewriteHandler(rewriters)
    const rewrittenRequest = handler.rewriteRequest(request.query!, request.variables)
    request.query = rewrittenRequest.query
    request.variables = rewrittenRequest.variables

    return {
      willSendResponse: resCtx => {
        const { response } = resCtx

        const newData = handler.rewriteResponse(response.data)
        response.data = newData
      },
    }
  },
})

[chanind]

This is a lot cleaner than the current implementation, thank you for doing this! I didn't realize Apollo directly allows rewriting responses like this so easily. Pending resolution of #28, I'll get a repo set up either in this org or in a new org and work on getting this merged!

[Sytten]

I faced an issue with the response, it duplicates the response payload for some reason for arrays. DO NOT USE until I fix it.

[Sytten]

Fixed in #29

[igrayson]

This implementation has worked well for us, notably overcoming graphql-query-rewriter/express-graphql-query-rewriter#6

However, it has one important bug: it throws an error within willSendResponse, when the response has no data (such as when the response only has application errors).

Fixed by adding a one-line check:

import { ApolloServerPlugin } from 'apollo-server-plugin-base'
import { RewriteHandler, Rewriter } from 'graphql-query-rewriter'

import { Context } from '~/context'

// An optimization that could be done is avoiding a query parsing
// and reprinting in the input. Not sure how to do this.
export const GraphQLQueryRewriter = (
  rewriters: Rewriter[]
): ApolloServerPlugin<Context> => ({
  requestDidStart(reqCtx) {
    const { request } = reqCtx

    const handler = new RewriteHandler(rewriters)
    const rewrittenRequest = handler.rewriteRequest(request.query!, request.variables)
    request.query = rewrittenRequest.query
    request.variables = rewrittenRequest.variables

    return {
      willSendResponse: resCtx => {
        const { response } = resCtx
        if (!response.data) return

        const newData = handler.rewriteResponse(response.data)
        response.data = newData
      },
    }
  },
})

An alternative fix would be to update RewriteHandler.rewriteResponse() to passthrough falsey response objects without inspecting them.

[Sytten]

Thanks for that, I will create an official package when I have time