🎯 Changes

Continues the recent test-quality series (e.g. #11057, #11093) by converting the toBeTruthy() / toBeFalsy() / toBeDefined() assertions in solid-query tests to exact assertions:

• QueryClientProvider — cache presence checks now assert the exact cached value (?.state.data) produced by the test's queryFn, and the cross-cache absence checks in the partitioning test use toBeUndefined() instead of not.toBeDefined(). One redundant existence check was removed where the next line already asserts ?.options.gcTime on the same query (it fails on undefined either way).
• suspense — the cache absence check before mount uses toBeUndefined() instead of toBeFalsy().
• useQuery — after the first fetch in the client-switch test, the presence check on queryClient1's cache now asserts the exact cached value.
• mutationOptions — removed expect(lastSnapshot[1]).toBeFalsy(): the preceding expect(lastSnapshot.length).toEqual(1) already guarantees there is no second entry.

One toBeDefined() is intentionally left in place: in useQuery → "should refetch query when queryClient changes", tightening the queryClient2 cache check to ?.state.data fails. After setClient(queryClient2), the second queryFn call actually lands in queryClient1's cache (its dataUpdateCount goes to 2) while the entry in queryClient2's cache stays status: 'pending' / fetchStatus: 'idle' and never fetches. This looks like an observer re-subscription ordering issue in useBaseQuery (in the on(client, ...) computed, createClientSubscriber() is called before setObserver(newObserver), so the subscription attaches to the old observer). I'd rather report and fix that separately than encode the current behavior into an exact assertion here.

After this, grep -rE 'toBeTruthy\(\)|toBeFalsy\(\)|toBeDefined\(\)' packages/solid-query/src only matches the site described above.

✅ Checklist

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

Local verification detail: vitest run on the four edited files — 162 tests passed, no type errors; test:eslint and prettier clean; full-suite failure set identical to main in the same environment.

🚀 Release Impact

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

Summary by CodeRabbit

• Tests
  • Strengthened cache validation to confirm stored query data and correct separation across caches.
  • Improved mutation state assertions to verify returned successful data.
  • Clarified unmount behavior by checking that removed queries are absent.
  • Tightened refetch validation to confirm expected cached results.