Fix useLiveQuery loading status in on-demand sync #962
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…sync For live queries using on-demand sync mode, the collection was being marked as ready immediately when source collections were ready, even though the initial loadSubset hadn't completed yet. This meant `isLoading` was false while data was still being fetched. This fix ensures that: 1. Live queries with on-demand sources track the initial loadSubset promise and show `isLoading: true` until it completes 2. The collection status remains `loading` until the first data load finishes 3. Subsequent loadSubset calls (pagination/windowing) do NOT affect the ready status - only the first load matters Changes: - Add `hasMarkedReady` and `hasSetupLoadingListener` flags to track initial ready state in CollectionConfigBuilder - Modify `updateLiveQueryStatus()` to wait for first loadSubset to complete before calling `markReady()` - Update `subscribeToMatchingChanges()` in CollectionSubscriber to track the initial loadSubset promise for on-demand sources - Add comprehensive tests for the new behavior
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Update test to wait for the initial loadSubset promise to resolve before checking the live query status. This is needed after the fix that makes live queries show loading status during initial on-demand data fetch.
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…romise: true For on-demand sync mode, the default includeInitialState path calls requestSnapshot with trackLoadSubsetPromise: false, which doesn't track the loading state. This change manually calls requestSnapshot with trackLoadSubsetPromise: true for on-demand sources to ensure the subscription status changes from 'loadingSubset' to 'ready' when data arrives. Also updates query-db-collection tests to use eager mode since they test TanStack Query cache behavior, not on-demand loading status.
samwillis
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Dec 16, 2025
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samwillis
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samwillis
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Looks good, just a couple of things to tweak I think.
| // Set up a one-time listener if we haven't already | ||
| if (!this.hasSetupLoadingListener) { | ||
| this.hasSetupLoadingListener = true | ||
| const unsubscribe = this.liveQueryCollection.on( |
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We should lift up the saved unsubscribe to save it at the top of the collection config builder level, then call it (if it exists) in the collection cleanup function. This is what we do with unsubscribeFromSchedulerClears - we should do the same as that.
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Could we add a test that checks this behaviour for an on-demand collection with a join to another on-demand collection. Check that it only modes to ready when both are not loading subsets.
…loading-status-01TNsEPERmfs3ub3e9iDRAzK
…DRAzK' of http://127.0.0.1:54067/git/TanStack/db into claude/fix-livequery-loading-status-01TNsEPERmfs3ub3e9iDRAzK
…eanup - Move loadingSubset listener unsubscribe to class property `unsubscribeFromLoadingListener` - Add cleanup call in sync cleanup function to prevent memory leaks - Add test verifying live query loading state tracks on-demand source loadSubset
Update react/todo and solid/todo examples to use ^1.0.8 to match other examples and pass sherif workspace version consistency check.
…DRAzK' of http://127.0.0.1:25666/git/TanStack/db into claude/fix-livequery-loading-status-01TNsEPERmfs3ub3e9iDRAzK
Verifies that when a live query joins two on-demand collections, the live query only becomes ready when BOTH sources have completed their loadSubset operations. Uses leftJoin to ensure predictable active/lazy source determination.
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For live queries using on-demand sync mode, the collection was being marked as ready immediately when source collections were ready, even though the initial loadSubset hadn't completed yet. This meant
isLoadingwas false while data was still being fetched.This fix ensures that:
isLoading: trueuntil it completesloadinguntil the first data load finishesChanges:
hasMarkedReadyandhasSetupLoadingListenerflags to track initial ready state in CollectionConfigBuilderupdateLiveQueryStatus()to wait for first loadSubset to complete before callingmarkReady()subscribeToMatchingChanges()in CollectionSubscriber to track the initial loadSubset promise for on-demand sources🎯 Changes
✅ Checklist
pnpm test:pr.🚀 Release Impact