Misleading type mentioned for 'formatResponse' in the docs

[asif-ir]

The type for formatResponse option is wrongly mentioned as Function though it is declared differently as (response: GraphQLResponse | null, requestContext: GraphQLRequestContext<TContext>) => GraphQLResponse in the code.

Docs Reference: https://github.com/apollographql/apollo-server/blob/master/docs/source/api/apollo-server.md#parameters

Code Reference:

apollo-server/packages/apollo-server-core/src/graphqlOptions.ts

Line 48 in 8059326

formatResponse?: (

(Note: This change was actually introduced in this commit.)

[dgurns]

Same issue here. Unless I'm misunderstanding something, looks like the formatResponse function type should allow returning GraphQLResponse | null.

Current:

formatResponse?: (
    response: GraphQLResponse | null,
    requestContext: GraphQLRequestContext<TContext>,
  ) => GraphQLResponse

Probably should be:

formatResponse?: (
    response: GraphQLResponse | null,
    requestContext: GraphQLRequestContext<TContext>,
  ) => GraphQLResponse | null

[glasser]

@asif-ir In general our API docs just say Function for any function type; if you need the more precise type, the TypeScript definitions are canonical.

@dgurns You're right that the typing looks wrong. Fixing in #5089.