fix: honor MCPServerRegistration targetRef namespace

[avinxshKD]

Fixes MCPServerRegistration reconciliation when spec.targetRef.namespace points at an HTTPRoute outside the registration namespace.

The API and docs allow this, and the field index/status update paths already account for it, but getTargetHTTPRoute always read the route from the MCPServerRegistration namespace.

This updates route lookup to use targetRef.namespace when set, with a regression test for cross-namespace refs.

Fixes: #1199

Tested:

• go test ./internal/controller

Summary by CodeRabbit

• Bug Fixes

  • Enhanced HTTPRoute target resolution to correctly derive namespace information from target references, with fallback to default namespace when not specified, enabling flexible cross-namespace HTTPRoute configuration.

• Tests

  • Added test coverage for namespace resolution behavior in HTTPRoute targeting.

[coderabbitai]

📝 Walkthrough

Walkthrough

getTargetHTTPRoute is updated to use mcpsr.Spec.TargetRef.Namespace when non-empty for the HTTPRoute lookup, falling back to mcpsr.Namespace. A new test, TestGetTargetHTTPRouteUsesTargetRefNamespace, validates this cross-namespace path with a fake client.

Changes

Cross-namespace HTTPRoute Lookup

Layer / File(s)	Summary
Namespace resolution + test internal/controller/mcpserverregistration_controller.go, internal/controller/mcpserverregistration_controller_test.go	getTargetHTTPRoute now conditionally reads TargetRef.Namespace before falling back to mcpsr.Namespace; new test builds a fake scheme/client, places an HTTPRoute in the target namespace, and asserts the correct namespace is returned.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~5 minutes

Suggested labels

review-effort/medium

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ 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%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main fix: enabling MCPServerRegistration to honor the targetRef namespace field for cross-namespace HTTPRoute references.
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[avinxshKD]

Hey @jasonmadigan fixed a small controller bug where MCPServerRegistration.spec.targetRef.namespace was ignored during HTTPRoute lookup....added a regression test and verified with go test ./internal/controller.

[Aman-Cool]

Thanks for this @avinxshKD, it's exactly the getTargetHTTPRoute namespace bug, and the fix looks right: it now honors targetRef.namespace and matches the status-writeback and watch-index paths, so all three finally agree.

I'd actually filed #1199 for this same bug just before David pointed me here.., could you add Fixes: #1199 to the description? (also clears the needs-issue label.)

A few notes while it's still draft, no rush:

• Test: nice cross-ns test 👍 could you also add the same-name edge case from MCPServerRegistration: targetRef.namespace is ignored during HTTPRoute resolution #1199 (a route with the same name in both namespaces, asserting it picks the targetRef one)? That silent mis-bind was the dangerous bit. The empty-namespace fallback would be good to assert too.
• DRY: the default-namespace logic now lives in 3 spots in two slightly different shapes; a tiny targetRefNamespace() helper would keep them from drifting again (operator: targetRef.namespace isn't defaulted to the extension's namespace, so same-namespace Gateways aren't found #1186 wants the same for MCPGatewayExtension).
• One question: should the cross-ns lookup be gated by a ReferenceGrant? Gateway API usually wants the target namespace's consent for a cross-ns ref, and we already do this for extension -> Gateway via HasValidReferenceGrant; totally fine as a follow-up if you'd rather keep this PR focused.

And whenever your primary PR merges (and if you've nothing else queued), would be great to bring this out of draft. happy to re-review and help get it over the line 🙂