fix: incorrect behavior for abstract types on required fields

[Noroth]

Related engine PR:
wundergraph/graphql-go-tools#1613

Summary by CodeRabbit

New Features

• Added employee recommendations for individual work items and lists of work items.
• Added latest work operation fields supporting approval and rejection results.
• Added nullable operation results when no applicable operation is available.
• Expanded support for nested interfaces, unions, aliases, lists, and batched employee requests.

Bug Fixes

• Improved null handling for missing employees and optional abstract-type results.
• Ensured combined scalar and abstract-type field requests resolve correctly.

Checklist

• I have discussed my proposed changes in an issue and have received approval to proceed.
• I have followed the coding standards of the project.
• Tests or benchmarks have been added or updated.
• If applicable, I have provided instructions for reviewers for manually validating my changes.
• Documentation has been updated on https://github.com/wundergraph/docs-website.
• I have read the Contributors Guide.

Open Source AI Manifesto

This project follows the principles of the Open Source AI Manifesto. Please ensure your contribution aligns with its principles.

[github-actions]

Router image scan passed

✅ No security vulnerabilities found in image:

ghcr.io/wundergraph/cosmo/router:sha-bb78af1fa8ddac50e7f38e6a95d66554e5023d8a

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: d16055be-1118-4392-9065-e220cada38d7

📥 Commits

Reviewing files that changed from the base of the PR and between 536bd54 and a75b1b8.

⛔ Files ignored due to path filters (2)

• router-tests/go.sum is excluded by !**/*.sum
• router/go.sum is excluded by !**/*.sum

📒 Files selected for processing (2)

• router-tests/go.mod
• router/go.mod

🚧 Files skipped from review as they are similar to previous changes (2)

• router-tests/go.mod
• router/go.mod

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Walkthrough

Changes

The projects subgraph adds four expertise-backed @requires fields that return interfaces and unions. gRPC resolvers, router fixtures, mappings, schemas, dependency versions, and protocol tests now cover abstract values, batching, nullability, aliases, and missing entities.

Abstract @requires resolution

Layer / File(s)	Summary
Employee abstract resolver contracts demo/pkg/subgraphs/projects/src/schema.graphql, demo/pkg/subgraphs/projects/src/service/service.go	Employee exposes interface and union fields. ProjectsService derives concrete results from expertise and field arguments.
Test environment schema and routing wiring router-tests/testenv/testdata/configWithGRPC.json	Fixture schemas, gRPC mappings, gateway requires selections, generated protocol schema, and field configurations are updated for the new fields and related fixture changes.
Abstract @requires protocol coverage router-tests/protocol/grpc_subgraph_test.go, router-tests/protocol/router_plugin_test.go, router-tests/go.mod, router/go.mod	Protocol tests cover abstract selections, lists, unions, nullability, batching, aliases, mixed requires, and missing entities. The GraphQL tools dependency is updated.

Estimated code review effort: 4 (Complex) | ~45 minutes

Possibly related PRs

• wundergraph/cosmo#2731: Extends Employee gRPC @requires resolution with an argument-based scalar field.
• wundergraph/cosmo#2913: Updates the same graphql-go-tools dependency in the router modules.
• wundergraph/cosmo#3101: Adds alias-focused tests for required-field resolution, which overlaps this PR’s abstract-type coverage.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the fix for incorrect abstract-type behavior on required fields.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.34%. Comparing base (e7d6208) to head (a75b1b8).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3130      +/-   ##
==========================================
+ Coverage   62.16%   62.34%   +0.18%     
==========================================
  Files         262      262              
  Lines       30978    30978              
==========================================
+ Hits        19258    19314      +56     
+ Misses      10199    10156      -43     
+ Partials     1521     1508      -13     

see 12 files with indirect coverage changes

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[dkorittki]

Don't forget to update engine