This expression is not callable. Not all constituents of type ... are callable.

[HarryDavisgithub]

Hi,
I am currently in the process of upgrading our graphql-codegen packages to latest(v 4.0.1). But am having issues with some types in resolvers. Specifically when trying to call a resolver from another resolver. Similar to this issue here. However this solution does not work for me. It looks like noSchemaStitching's default is true now (perhaps wasn't before?)

Current versions:
"@graphql-codegen/typescript": "^1.21.1", "@graphql-codegen/typescript-resolvers": "^1.19.0",

File structure:

└── /entities                       
    └── /**                         # One dir per GraphQL Type
        └── *.schema.graphql        # Define type schema
        └── /resolvers
            └── /Query.ts           # Merged onto the root query
            └── /Mutation.ts        # Merged onto the root mutation
            └── /*.ts               # Type Resolvers
└── /generated                      # Code-generated schema and openapi types 
    └── graphql.ts                    # Generated by code-gen
└── /graphql.schema.json            # Generated schema metadata

.graphqlrc.yml:

schema:
  - server/graphql/**/*.schema.graphql

documents:
  - src/components/**/*.query.graphql
  - src/components/**/*.mutation.graphql
  - src/components/**/*.fragment.graphql

extensions:
  codegen:
    config:
      enumsAsTypes: true
      declarationKind: interface
      dedupeOperationSuffix: true
      immutableTypes: true
      namingConvention: keep
      noSchemaStitching: true
      operationResultSuffix: Data
      optionalResolveType: true
      useIndexSignature: true
      customResolverFn: >
        (
          parent: TParent,
          args?: TArgs,
          context?: ApolloContext,
          info?: GraphQLResolveInfo
          ) =>
            Promise<TResult> | TResult

    generates:
      server/graphql/graphql.schema.json:
        plugins:
          - introspection

      server/graphql/generated/graphql.ts:
        config:
          contextType: ApolloContext
          mappers:
            <bunch of mappers>

        plugins:
          - typescript
          - typescript-resolvers

Example type resolver causing issue:

import { MyResolverResolvers } from "/graphql/generated/graphql"
export const MyResolver: MyResolverResolvers = {

  async addNumbers(parent, args, context, info) {
    return args.number + MyResolver.getNumber5(parent, args, context, info)
  }

  async getNumber5(parent, _, context) {
    return 5;
  }
}

Trying to call MyResolver.getNumber5() like this will give:

  This expression is not callable.
  Not all constituents of type 
  Resolver<ResolverTypeWrapper<number>, parent type here, ApolloContext, {}>' are callable. 
  Type 'ResolverWithResolve<ResolverTypeWrapper<number>, parent type here, ApolloContext, {}>' has no call signatures

Any suggestions welcome. I currently just want to update the packages, in the future look into using something like the server-preset.
Thanks!

[vaughandroid]

So, the GraphQL tools support both resolvers which are functions, and resolvers which are objects which have a resolve() function. The generated types reflect this.

You can add the config option makeResolverTypeCallable: true which will tell the type generator to only generate types for resolvers which are functions. This should solve your issue.