fix: support requireFetchReasons on interface fields

[ysmolski]

When an interface field is marked,
and a user requests that field in an operation,
then fetch reasons for this field will be extended
with fetch reasons for all the implementing types.

In general, a marked interface field leads to all
implementation's fields being used for propagation.

I have removed special config needed for testing fetch reasons.
Instead I added those directives to the demo package.

Bumped the shoenig/go-m1cpu package to get rid of warnings from xcode 26.

Summary by CodeRabbit

• New Features

  • Added a repeatable GraphQL directive (openfed__requireFetchReasons) usable on fields, interfaces, and objects.
  • Router now includes fetch_reasons data in response extensions when the directive is applied (e.g., on employee and Query fields).

• Tests

  • Expanded integration tests to verify rendered subgraph queries and the presence of fetch_reasons in extensions.

• Chores

  • Upgraded dependencies, including graphql-go-tools to v2.0.0-rc.230 and go-m1cpu to v0.1.7.

[coderabbitai]

Walkthrough

Dependency bumps in go.mod files, a new repeatable GraphQL directive added and applied in the employees subgraph schema, router tests updated to use a different config template and to assert fetch_reasons in extensions, and a testenv exported template variable removed.

Changes

Cohort / File(s)	Summary of changes
Go module updates demo/go.mod, router/go.mod, router-tests/go.mod	Bumped dependencies: github.com/shoenig/go-m1cpu v0.1.6 → v0.1.7; github.com/wundergraph/graphql-go-tools/v2 rc.229 → rc.230 (router and router-tests).
Subgraph schema directive demo/pkg/subgraphs/employees/subgraph/schema.graphqls	Added repeatable directive @openfed__requireFetchReasons (FIELD_DEFINITION, INTERFACE, OBJECT). Applied to employee(id: Int!): Employee field and interface Identifiable.
Router tests updates router-tests/integration_test.go, router-tests/testenv/testenv.go	Tests: switched RouterConfigJSONTemplate to testenv.ConfigJSONTemplate; added assertions for rendered query and extensions.fetch_reasons for Employee and Query. Testenv: removed exported ConfigWithRequireFetchReasonsJSONTemplate and its embed.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• feat: send to subgraphs the "fetch_reasons" extension #2160 — Introduces and tests requireFetchReasons/@openfed__requireFetchReasons and assertions on extensions.fetch_reasons, aligning with this PR’s schema and test updates.
• fix: fix detecting requires on interface members for abstract selection rewriter #2209 — Adds/tests @openfed__requireFetchReasons on interface members and updates graphql-go-tools, matching this PR’s interface directive usage and dependency bump.

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The pull request title accurately captures the core change of enabling the requireFetchReasons directive on interface fields and is both concise and specific to the implemented modifications.

✨ Finishing touches

• 📝 Generate docstrings

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📜 Recent review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2a31f95 and e74e094.

⛔ Files ignored due to path filters (3)

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

📒 Files selected for processing (6)

• demo/go.mod (1 hunks)
• demo/pkg/subgraphs/employees/subgraph/schema.graphqls (2 hunks)
• router-tests/go.mod (2 hunks)
• router-tests/integration_test.go (2 hunks)
• router-tests/testenv/testenv.go (0 hunks)
• router/go.mod (2 hunks)

💤 Files with no reviewable changes (1)

• router-tests/testenv/testenv.go

🧰 Additional context used

🧠 Learnings (1)

📚 Learning: 2025-08-20T22:13:25.222Z

Learnt from: StarpTech
PR: wundergraph/cosmo#2157
File: router-tests/go.mod:16-16
Timestamp: 2025-08-20T22:13:25.222Z
Learning: github.com/mark3labs/mcp-go v0.38.0 has regressions and should not be used in the wundergraph/cosmo project. v0.36.0 is the stable version that should be used across router-tests and other modules.

Applied to files:

• router-tests/go.mod

🧬 Code graph analysis (1)

router-tests/integration_test.go (1)

router-tests/testenv/testenv.go (1)

• ConfigJSONTemplate (81-81)

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• GitHub Check: integration_test (./events)
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• GitHub Check: Analyze (go)
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🔇 Additional comments (8)

demo/go.mod (1)

130-130: LGTM!

The minor version bump to v0.1.7 eliminates warnings from Xcode 26 as stated in the PR description and is coordinated with similar updates across other modules.

router/go.mod (1)

34-34: LGTM!

Both dependency bumps are appropriate:

• graphql-go-tools/v2 → rc.230 provides support for the requireFetchReasons directive feature
• shoenig/go-m1cpu → v0.1.7 eliminates Xcode 26 warnings

The updates are coordinated with similar changes across other modules in this PR.

Also applies to: 151-151

router-tests/go.mod (1)

30-30: LGTM!

The dependency updates are properly coordinated with other modules:

• graphql-go-tools/v2 → rc.230 enables testing of the requireFetchReasons directive
• shoenig/go-m1cpu → v0.1.7 eliminates Xcode 26 warnings

Note: mark3labs/mcp-go correctly remains at v0.36.0 (the stable version).

Based on learnings.

Also applies to: 137-137

demo/pkg/subgraphs/employees/subgraph/schema.graphqls (3)

27-28: LGTM!

The directive declaration is well-defined:

• Marked as repeatable for flexibility
• Targets appropriate schema locations: FIELD_DEFINITION, INTERFACE, and OBJECT
• Naming convention with openfed__ prefix follows OpenFederation standards

---

30-30: LGTM!

Applying @openfed__requireFetchReasons to the employee field ensures fetch reasons are tracked for this Query field, as verified by the test assertions in integration_test.go (line 856).

---

85-87: LGTM!

Applying @openfed__requireFetchReasons to the Identifiable interface correctly enables fetch reason tracking for the id field on all implementing types (e.g., Employee). This is verified by the test assertion in integration_test.go that checks for {"typename":"Employee","field":"id","by_user":true} in the fetch_reasons extension.

router-tests/integration_test.go (2)

841-841: LGTM!

Excellent refactoring. The test now uses the standard testenv.ConfigJSONTemplate instead of a special template, as the requireFetchReasons functionality is now controlled by schema directives rather than configuration. This makes the feature more explicit and maintainable.

---

853-856: LGTM!

The assertions correctly verify that the @openfed__requireFetchReasons directive works on both:

1. Query fields (Query.employee from line 30 of schema.graphqls)
2. Interface fields (Employee.id inherited from Identifiable interface at line 85 of schema.graphqls)

The expected fetch_reasons extension data matches the directive applications in the schema.

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[github-actions]

Router image scan passed

✅ No security vulnerabilities found in image:

ghcr.io/wundergraph/cosmo/router:sha-5c565c39c8ef7ec97f17224ca7271eaa67944c3b

[Aenimus]

LGTM!