🎯 Changes

QueryCache/MutationCache subscribe callbacks receive an event object whose query/mutation is an instance the library creates internally. Several tests only checked that the callback fired (toHaveBeenCalled()) or matched the type field partially (objectContaining), leaving the instance and the exact payload shape unverified.

Each test can recover the instance from the cache (find({ queryKey }), or the in-scope mutation/observer), so the assertions now pin the full event object. Where the callback fires multiple times in a known order, the assertion is also pinned to the right call (added is the first event, removed from gc is the last).

• queryCache — added events (4 tests) — assert toHaveBeenNthCalledWith(1, { query, type: 'added' }); added is always the first event, and the earlier toHaveBeenCalledWith/toHaveBeenCalled() did not pin the call position
• mutationCache — "should still notify removal..." — dropped objectContaining so { type: 'removed', mutation } also asserts no extra fields (single call is already guaranteed by toHaveBeenCalledTimes(1))
• query — "queries should be garbage collected even if they never fetched" — captures the query before gc removes it, then asserts toHaveBeenLastCalledWith({ type: 'removed', query }) (gc removal is the last event)
• queryObserver — "should notify cache listeners when setOptions is called" — asserts the full { type: 'observerOptionsUpdated', query, observer } (single call is already guaranteed by toHaveBeenCalledTimes(1))
• queryClient — "should notify listeners when a query is reset" — toHaveBeenCalled() → toHaveBeenNthCalledWith(1, objectContaining({ type: 'updated', query, action: { type: 'setState' } })) (the action.state snapshot is left open, as it depends on timing)

✅ Checklist

• I have followed the steps in the Contributing guide.
• I have tested this code locally.

🚀 Release Impact

• This change is docs/CI/dev-only (no release).

Summary by CodeRabbit

• Tests
  • Strengthened cache and observer notification tests to verify complete event payloads.
  • Added precise assertions for query and mutation additions, removals, updates, garbage collection, and option changes.
  • Improved validation of callback invocation order and associated query, observer, and action details.