delegate with valuesFromResults missing id

[cassidycodes]

Hello, we noticed that this PR broke how we use valuesFromResults: #6134

We have a stitched schema that merges a few types. The type Account is shared across many services. Account.id is resolved in a local resolver that is stitched into the main schema.

And two of our subschemas have Account merge arguments with a valuesFromResults function that looks like this:

valuesFromResults: (results, keys) => {
  const resultsHash = Object.fromEntries(
    results.map((account: any) => [account.id, account]),
  );
  return keys.map((key) => resultsHash[key] ?? { id: key });
},

The reason for this valuesFromResults is that some services may respond with fewer Account objects than requested. In @graphql-tools/[email protected], this function worked for us. But with the upgrade to 10.0.5 this function no longer works because results does not have an id field.

I believe id is removed in this line:

graphql-tools/packages/delegate/src/prepareGatewayDocument.ts

Line 270 in 66c99d9

const unavailableFields = extractUnavailableFields(schema, field, selection, shouldAdd);

because id is already available.

Are we doing something unconventional here, or should id remain a part of the results objects?

[cassidycodes]

@ardatan Here is a PR with a failing test where valuesFromResults returns null because the id is not present. Based on the tests here it seems like the id is being dropped from results after the request to the backend is made.

For additional context, our project is on the following versions:

• [email protected]
• [email protected]
• [email protected]
• [email protected]
• [email protected]
• [email protected]