[apollo federation] map injection doesn't work in reference resolver

[dariuszkuc]

Is there an existing issue for this?

• I have searched the existing issues

Product

Hot Chocolate

Describe the bug

When implementing Federation reference resolver it should be possible to inject parameters using Map["some.key"] syntax. Syntax works when there are other keys present (link) but fails when we only use map key (link).

Steps to reproduce

1. Check out https://github.com/apollographql/apollo-federation-subgraph-compatibility/tree/hotchocolate

• Test project is under https://github.com/apollographql/apollo-federation-subgraph-compatibility/tree/hotchocolate/implementations/hotchocolate
• class that is showing issue -> https://github.com/apollographql/apollo-federation-subgraph-compatibility/blob/hotchocolate/implementations/hotchocolate/Types/ProductResearch.cs

2. Build test harness by running make setup (from root project directory)
3. Run make test subgraph=hotchocolate (from root project directory)
4. See that test verifying composite key (@key (composite)) fails

Relevant log output

No response

Additional Context?

If you update the entity resolver of ProductResearch (linked above) type to use ObjectValueNode you can see that received entity object reference has expected values.

Version

13.0.0

[dariuszkuc]

resolved by #6596