selectionSet is not passed to delegateToSchema/batchDelegateToSchema when using GraphQL Handlers

[marcammann]

Describe the bug
When I was trying to use the (very convenient) way of accessing the API clients for GraphQL handlers, I found myself using selectionSet to be able re-map fields. I found it more convenient than using delegateToSchema or batchDelegateToSchema. However, the selectionSet when using an API SDK function is not being passed on to delegateToSchema / batchDelegateToSchema. Currently, a transform is created that transforms the request, but that only transforms the field if there is a selectionSet attached to a particular node in the original request. If the original request was for a scalar node, then there is no selectionSet associated and the request is not transformed.

To Reproduce
Steps to reproduce the behavior:

Using this in my resolver:

headline: {
      selectionSet: /* GraphQL */ `
        {
          id
        }
      `,
      resolve: async (root, args, context, info) => {
        const result = await context.Artifacts.Query.artifactsByIds({
          root,
          argsFromKeys: (keys: string[]) => {
            return { ids: keys }
          },
          key: root.id,
          context,
          info,
          selectionSet: /* GraphQL */ `
            {
              headline
            }
          `,
        })

        console.log('Headline Result: ', result)

        return result.headline
      },
    },

Expected behavior

In the above I'd expect that there is a GraphQL request being made with the selectionSet { headline }, but it is actually never attached and thus never returns any data for that headline.

I believe this is due to the fact that the request is only transformed if the original request (in the info object) also had a selectionSet. I think instead we should pass along the selectionSet into delegateToSchema / batchDelegateToSchema. I believe the relevant location is commonDelegateOptions on line 213 of get-mesh.ts.

Environment:

• OS:

"@graphql-mesh/cli": "0.37.0",
    "@graphql-mesh/graphql": "0.18.9",
    "@graphql-mesh/transform-encapsulate": "0.1.57",
    "@graphql-mesh/transform-naming-convention": "0.6.59",
    "@graphql-mesh/transform-prefix": "0.6.58",
    "@graphql-mesh/transform-rename": "0.9.8",
    "@graphql-tools/batch-delegate": "8.0.12",
    "@graphql-tools/delegate": "8.1.1",

• NodeJS: