TypeScript: Property 'mergeInfo' is missing in type 'GraphQLResolveInfo' but required in type '{ mergeInfo: MergeInfo; }

I am using this library and for the last year I loved it. Now I am using it in a TypeScript GraphQL Server with @types/graphql-resolvers.

All my types are generated via graphql-codegen. Without combineResolvers, all types evaluate just fine. If I am using a combined resolver though, I get:

Type 'IFieldResolver<any, any, { courseId: COURSE; bundleId: BUNDLE; }>' is not assignable to type 'ResolverFn<any, {}, ResolverContext, RequireFields<MutationCreateFreeCourseArgs, "courseId" | "bundleId">> | StitchingResolver<...> | undefined'.
  Type 'IFieldResolver<any, any, { courseId: COURSE; bundleId: BUNDLE; }>' is not assignable to type 'ResolverFn<any, {}, ResolverContext, RequireFields<MutationCreateFreeCourseArgs, "courseId" | "bundleId">>'.
    Types of parameters 'info' and 'info' are incompatible.
      Type 'GraphQLResolveInfo' is not assignable to type 'GraphQLResolveInfo & { mergeInfo: MergeInfo; }'.
        Property 'mergeInfo' is missing in type 'GraphQLResolveInfo' but required in type '{ mergeInfo: MergeInfo; }'.ts(2322)
Interfaces.d.ts(59, 5): 'mergeInfo' is declared here.
gen-types.ts(288, 3): The expected type comes from property 'createFreeCourse' which is declared here on type 'WithIndex<{ _?: ResolverFn<any, {}, ResolverContext, {}> | StitchingResolver<any, {}, ResolverContext, {}> | undefined; ... 8 more ...; createAdminCourse?: ResolverFn<...> | ... 1 more ... | 

Whereas I think the crucial part is:

Property 'mergeInfo' is missing in type 'GraphQLResolveInfo' but required in type '{ mergeInfo: MergeInfo; }'.ts(2322)

Could it be that the 4th argument of a resolver isn’t evaluated in the TS version of this library?

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Something related in another library: https://github.com/prisma-labs/graphql-middleware/pull/29/files

[zaguiini]

Types have been published. Can you try it again?

[lucasconstantino]

@rwieruch are you TypeScript acknowledged? I’ve being using for a while, but I’m no expert. To give you context: this library has currently no typings at all, and I don’t even know where to start with typing cause this library has no direct relation with GraphQL. Take combineResolvers, for instance:

combineResolvers: (...args: any[]) => Promise<any>

The any[] is because this is precisely how this library works: whatever it takes in, it will manage to make available to the end of the cycle.

We could use generics an inference to help typing resolver implementations from whatever is arguments are passed into combineResolvers, but I’m not really sure how to accomplish that. I’m very open to PRs, though.

P.s.: a easy solution for you own case would be to create your own strict type definition… keep in mind this wouldn’t be a got fit for contributing, cause this varies a lot. context, for instance, is basically a black box for typing, no way we should interfere on how that is typed, or we would probably cause more trouble than gain.