IFieldResolver args should allow typing

[thevtm]

I've been using Apollo's GraphQL solutions for a while and I find them amazing, really good work. 👍
So I was updating some dependencies in a project and I got this type error that wasn't occurring before the update. 🐛

Expected Behavior

import { IResolvers } from "graphql-tools/dist/Interfaces";

interface IGQLUser {
  id: string;
  name: string;
}

interface IUserResolverArgs {
  id: string;
}

export async function userResolver(obj: any, args: IUserResolverArgs): Promise<IGQLUser | null> {
  return { id: args.id, name: "Frank" };
}

const resolver: IResolvers = {
  Query: {
    user: userResolver,
  },
};

This code to not error.

Actual Behavior

Error

TS2322: Type '{ Query: { user: (obj: any, args: IUserResolverArgs) => Promise<IGQLUser | null>; }; }' is not assignable to type 'IResolvers'.
Property 'Query' is incompatible with index signature.
  Type '{ user: (obj: any, args: IUserResolverArgs) => Promise<IGQLUser | null>; }' is not assignable to type '(() => any) | IResolverObject | GraphQLScalarType'.
    Type '{ user: (obj: any, args: IUserResolverArgs) => Promise<IGQLUser | null>; }' is not assignable to type 'GraphQLScalarType'.
      Property 'name' is missing in type '{ user: (obj: any, args: IUserResolverArgs) => Promise<IGQLUser | null>; }'.

Specifications

• Version: 1.1.0

Suggested solution

Use the graphql-js implementation like in the previous versions.

export type GraphQLFieldResolver<
  TSource,
  TContext,
  TArgs = { [argument: string]: any },
> = (
  source: TSource,
  args: TArgs,
  context: TContext,
  info: GraphQLResolveInfo,
) => mixed;

[corydeppen]

I continue to run into this as well. Turning strictFunctionTypes off gets rid of the error, but it's clearly a hack. This seems related to DefinitelyTyped/DefinitelyTyped#21359, which I still feel is unresolved. If TS can't be used with strict flags enabled, I think the typings may need to be firmed up.

[stubailo]

Let's keep track of typescript improvements in #704