[Test]: Add unit tests for pkg/controllers/exceptions package

Kyverno Version

1.18.0

Description

Summary

The pkg/controllers/exceptions package responsible for managing and indexing PolicyException objects for quick rule-based lookups currently has zero unit tests.

Proposed Changes / Scope

Add comprehensive unit tests in pkg/controllers/exceptions/controller_test.go to ensure correctness and prevent future regressions:

1. Lookup Logic (Find):

   • Querying an empty index returns nil without errors.
   • Exact hits for matching policy and rule names.
   • Misses when querying non-existent policies or rules.

2. Event Handlers (addPolex, updatePolex, deletePolex):

   • Enqueueing referenced policy names into the workqueue.
   • Deduplication of policy names within the same exception.
   • Enqueueing the union of policy names during exception updates.

3. Reconciliation (reconcile):

   • Building and updating the policy-rule index for both ClusterPolicy and namespaced Policy resources.
   • Proper deletion of cache entries when a policy is deleted (NotFound).
   • Namespace scoping: ensuring a controller configured for a specific namespace only indexes exceptions from that namespace.
   • Deterministic ordering of exceptions by (namespace, name).

4. Concurrency & Thread Safety:

   • Concurrent Find operations across multiple goroutines.
   • Concurrent reconcile (writes) and Find (reads) verified under Go race detector (-race).

Benefit

Improves test coverage for exception controller caching and guarantees thread-safe index mutation and lookup.

Slack discussion

No response

Troubleshooting

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