Nested entity from a custom mutation result fails at runtime

[eddiesholl]

Describe the bug
The resolver for a nested entity (batchCode in this case) is failing at runtime when I have selected a list of entities with a child entity. The selection is coming off the result of a custom mutation.

Cannot read properties of undefined (reading 'batchCode')\n    at id .../src/packages/backend/.graphweaver/backend/index.js:768:51)\n    at _listRelationshipField (.../src/node_modules/.pnpm/@exogee+graphweaver@2.9.7_encoding@0.1.13/node_modules/@exogee/graphweaver/lib/resolvers.js:380:15)

I believe the problem is at this line of code. The source must be a graphql entity that does not have the 'dataEntity' populated

graphweaver/src/packages/core/src/resolvers.ts

Line 566 in c5cfe2a

idValue = id(dataEntityForGraphQLEntity<G, D>(source as any));

To Reproduce
Steps to reproduce the behavior:

1. Define an entity that has a nested entity
2. Create a custom mutation that returns a list of the parent entities
3. The mutation should return microform entity instances
4. Select the 2 levels of entities

Expected behavior
This should not fail at runtime

Actual behavior
It throws an error

Screenshots or Screencasts

Desktop (please complete the following information):

• MacOS 14.4

Additional context
@thekevinbrown has a pretty good sense of what is probably wrong here

[thekevinbrown]

So, the solution here I'm 99% sure is to call fromBackendEntity() on the things you get back before you return them. It could be nice to not have to do this, but I think what we should do now is:

• Provide a clear example of how to do custom mutations and queries in the examples folder.
• This should include nested results from a custom mutation and custom query.
• Update the docs to have a page on this specifically so that someone who wants to implement custom queries and / or mutations understands how to:
  • Register them
  • Build a resolver
  • How to disable all built in queries and mutations for an entity.
  • The security implications (we don't enforce ACLs for custom queries and mutations so they'll need to do it themselves).
  • Joining back to the default resolvers, e.g. here's a custom query that returns tasks.