Default plan resolver should use .get(...) if possible

[eugeneduda]

Summary

When I try to wrap a step result in object I get an error:

Error: The step returned by 'createAsset.asset' is not compatible with the GraphQL object type 'Asset': Expected a PgSelectSingleStep, PgInsertSingleStep, PgUpdateSingleStep or PgDeleteSingleStep, however we received 'Access{2}➊<35.asset>[42]'.

Steps to reproduce

A code example:

makeExtendSchemaPlugin((build) => {
   const { assets } = build.input.pgRegistry.pgResources;
   if (!assets) throw new Error("...");

   return {
     typeDefs: gql`
       type CreateAssetPayload {
         asset: Asset!
       }

       CreateAssetInput {
        ...
       }
  
       extend type Mutation {
         createAsset(input: CreateAssetInput!): CreateAssetPayload
       }
     `,
     plans: {
       Mutation: {
         createAsset() {
           const $id = withPgClient(...);

           return object({ asset: assets.get({ id: $id }) });
         }
       }
     }
   }
});

There is no problem when it returns assets.get({ id: $id })

The issues will be fixed if you add the following plan:

CreateAssetPayload: { 
    asset($payload) { 
        return $payload.get(‘asset’);
    } 
}

Expected results

You don't have to add the CreateAssetPayload plan resolver

Additional context

My PostGraphile version is 5.0.0-beta.35

[benjie]

Hmmm... This is weird because it should work:

crystal/grafast/grafast/src/engine/OperationPlan.ts

Lines 3799 to 3806 in 5dd99a0

	function makeDefaultPlan(fieldName: string) {
	return (
	$step: ExecutableStep & { get?: (field: string) => ExecutableStep },
	) =>
	typeof $step.get === "function"
	? $step.get(fieldName)
	: access($step, [fieldName]);
	}

crystal/grafast/grafast/src/engine/OperationPlan.ts

Lines 1091 to 1093 in 5dd99a0

	const planResolver =
	rawPlanResolver ??
	(resolver ? undefined : makeDefaultPlan(fieldName));

[benjie]

Are you using makeWrapPlansPlugin perchance? I don't see it in your "reproduction", so I assume not? I've not tried to reproduce it yet, because your reproduction is just an excerpt rather than something runnable.

[benjie]

I think you must be using makeWrapPlansPlugin and you're wrapping this resolver on the mutation payload for some reason; I can see that the fallback in makeWrapPlansPlugin is the old-style default plan which doesn't use get:

crystal/graphile-build/graphile-utils/src/makeWrapPlansPlugin.ts

Lines 145 to 151 in 5dd99a0

	plan: oldPlan = EXPORTABLE(
	(access, fieldName) =>
	// eslint-disable-next-line @typescript-eslint/consistent-type-imports
	($obj: import("grafast").ExecutableStep) =>
	access($obj, fieldName),
	[access, fieldName],
	),

Please confirm whether or not this is the case.

Either way, please actually create and share a minimal reproduction in future and test that it reproduces the issue rather than just sharing a small excerpt of what you think is causing it; it will likely save me significant time. We're lucky I could intuit it this time around... assuming I'm correct.

[eugeneduda]

Yes. I think you are right. I will make an exact reproduction of the error and reopen the issue

[benjie]

Either way, the makeWrapPlansPlugin default resolver needs fixing so I'll leave it open.