Feature request: GraphQL API Event Handler

[hjgraca]

Use case

Related to the issue and feature request in Typescript aws-powertools/powertools-lambda-typescript#1166

Now that .NET has an Event Handler for AppSync we should also support GraphQL
Add the ability to register single resolvers for AppSync GraphQL API.

Solution/User Experience

GraphQL API handler in Lambda Powertools for Python has a resolver library which does the nested resolution inside a single lambda function and instead of creating the abstraction on infrastructure level, as AppSync does, it creates it on source code level. This resolution can be done thanks to informations from $ctx.info.

This way lambda resolvers would be only for top-level Mutation/Query fields and the rest would be done inside lambda function(s).

Alternative solutions

Acknowledgment

• This feature request meets Powertools for AWS Lambda (.NET) Tenets
• Should this be considered in other Powertools for AWS Lambda languages? i.e. Python, Java, and TypeScript