frontend: project: Fix ProjectList crash when a namespace has no labels

[govindup63]

Summary

This PR fixes a TypeError that crashed the Projects page whenever the list returned from Namespace.useList contained a namespace without metadata.labels populated. The Projects view simply went blank with this error in the console:

TypeError: Cannot read properties of undefined (reading 'headlamp.dev/project-id')

The crash originated on frontend/src/components/project/ProjectList.tsx, where the groupBy iteratee dereferenced n.metadata.labels![PROJECT_ID_LABEL] with a non-null assertion. The labelSelector on the API request filters at the server side, but the array reaching groupBy can still transiently include namespaces without metadata.labels populated, for example during multi-cluster fan-out or while the react-query cache is being refreshed after a label removal.

Related Issue

Fixes #5254

Changes

• frontend/src/components/project/ProjectList.tsx: extract the namespaces-to-projects transformation into a small exported helper groupNamespacesIntoProjects and filter out items that do not carry PROJECT_ID_LABEL before grouping. The useProjects hook now calls the helper and tolerates Namespace.useList returning items: null.
• frontend/src/components/project/ProjectList.test.tsx: new vitest suite covering normal grouping, multi-cluster collection, and the two regression cases from Crash Report: Cannot read properties of undefined (reading 'headlamp.dev/project-id') #5254 (a namespace whose metadata.labels is undefined, and a namespace whose labels object is present but does not include PROJECT_ID_LABEL).

Steps to Test

1. Check out this branch and run npm install under frontend/ if needed.
2. npx vitest run src/components/project/ProjectList.test.tsx. All four tests should pass.
3. Reverting only the filter inside groupNamespacesIntoProjects reproduces the original crash from Crash Report: Cannot read properties of undefined (reading 'headlamp.dev/project-id') #5254 with the exact error message, which the new tests catch.
4. npx tsc --noEmit and npx eslint -c package.json src/components/project/ProjectList.tsx src/components/project/ProjectList.test.tsx are clean.

Notes for the Reviewer

• The label selector still filters at the API layer, so under steady state the new filter is a no-op. Its only job is to keep the inner iteratee safe against transient cache contents.
• The helper is exported rather than inlined into useProjects so it can be tested directly without an RTL harness. Following the cyclic-import workaround already used by projectUtils.test.ts (the _dont_delete_me = App import) was the cheapest way to make the new test load.
• No behavior change for users whose namespaces are all labelled correctly: the helper output is identical to the previous expression in that case.

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[Copilot]

Pull request overview

Fixes a crash in the Projects page caused by dereferencing metadata.labels[PROJECT_ID_LABEL] when a Namespace item transiently lacks metadata.labels (e.g., during cache refresh or multi-cluster fan-out).

Changes:

• Added groupNamespacesIntoProjects helper to safely group namespaces by PROJECT_ID_LABEL, filtering out entries without that label before groupBy.
• Updated useProjects to tolerate Namespace.useList returning items: null by defaulting to an empty list.
• Added a new Vitest suite covering normal grouping, multi-cluster behavior, and the two regression scenarios from #5254.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
frontend/src/components/project/ProjectList.tsx	Prevents Projects page crash by filtering namespaces lacking metadata.labels[PROJECT_ID_LABEL] before grouping; handles items: null.
frontend/src/components/project/ProjectList.test.tsx	Adds unit tests for the grouping helper, including regressions for missing labels / missing project-id label.

[illume]

🎉 thanks!

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: govindup63, illume

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