[feature] async formatResponse and formatError

[vinicius73]

Hooks formatResponse and formatError do not accept async operations.
Tools that report errors are difficult to use because formatError does not support async operations.
I particularly need to perform some operations with each graphql response, I can not because formatResponse is not async.

I'm doing tests and adjustments and I intend to send a PR soon, before I'm starting a dialogue about it.

Related #1748

[dunika]

I'm running into an issue with with AWS Lambda. I am sending my error to sentry inside formatError but this is an asynchronous operation so there is a chance that the function will close before the message is sent.

[tanduong]

Same!

[BrenoMazieiro]

Same

[KyleAWang]

Same. I need some data from cache or db to decorate response. How can I do it without async support?!

[Renaud009]

Any workaround for this? I need to make an http call (apollo-rest-datasource) under certain conditions before returning response (formatResponse).

Couldn't find any other Apollo Server function that executes after all resolvers are resolved.

I actually am using Sentry too to report any error occuring in formatError function, but errors are generally sent so I didn't except to have a problem with this until reading this issue.

[bertero]

@vinicius73 any news here? I am facing the same issue...

@dunika My problem is exactly the same, using a very similar stack. Were you able to solve it?

[martijnwalraven]

This should be possible by using the new request pipeline plugin API. willSendResponse can be async and will allow you to modify the response. For error reporting, didEncounterErrors (#2719) is the hook to use.

[dunika]

@martijnwalraven I can't find anything in the docs any of this. Has this been released?

Do you have an example of where/how the didEncounterErrors hook is used?

@bertero Sorry for the late response I havn't implemented any solution for this but you could use graphql-middleware](https://github.com/prisma/graphql-middleware) to do I I'd say

[taikn]

@dunika Docs seem to be still WIP, I found a preview here:
https://github.com/apollographql/apollo-server/blob/abernix/docs-plugins/docs/source/features/plugins.md
and here is the example of using the hook:
#1709 (comment)