packages/query-core/src/__tests__/queriesObserver.test.tsx (1)

652-660: This test can pass even if combine recomputes.

At Line 659, toBe alone doesn’t prove the cached branch was hit, because replaceEqualDeep can still return the previous reference after a recomputation with equal output. Please also assert that combine is not called again on the second pass.

Proposed test hardening

     const [raw1, getCombined1] = observer.getOptimisticResult(queries, combine)
     const combined1 = getCombined1(raw1)
+    const callsAfterFirst = combine.mock.calls.length

     const [raw2, getCombined2] = observer.getOptimisticResult(queries, combine)
     const combined2 = getCombined2(raw2)

     // Same combine, same queries → cached result returned
+    expect(combine.mock.calls.length).toBe(callsAfterFirst)
     expect(combined1).toBe(combined2)

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@packages/query-core/src/__tests__/queriesObserver.test.tsx` around lines 652
- 660, The test currently only asserts reference equality
(expect(combined1).toBe(combined2)) which can pass even if combine recomputed;
update the test to ensure combine is not invoked on the second call by using a
spy/mocked function for combine (e.g., replace the plain combine with a jest.fn
or equivalent) and assert its call count before and after the second getCombined
call when calling observer.getOptimisticResult(queries, combine) and
getCombined2(raw2); specifically reference the combine function and
observer.getOptimisticResult to locate where to wrap combine and add an
assertion like expect(combine).not.toHaveBeenCalledTimes/incremented on the
second pass in addition to the existing toBe assertion.