Remove flushSync from svelte-db to avoid breaking async compiler mode#745
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KyleAMathews merged 8 commits intomainfrom Nov 5, 2025
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…r mode Fixes #744 The flushSync() call inside the onFirstReady callback was breaking Svelte 5's async compiler mode. The async compiler enforces a rule that flushSync cannot be called inside effects, as documented at svelte.dev/e/flush_sync_in_effect. The fix removes the flushSync call and updates status directly. Svelte's reactivity system handles the update automatically without needing synchronous flushing. This matches the pattern used in Vue's implementation. Changes: - Removed flushSync() wrapper from onFirstReady callback - Removed unused flushSync import - Updated comment to explain why flushSync cannot be used - All 23 existing tests pass, confirming no regression This fix is backward compatible: - For users WITHOUT async mode (current default): Works as before - For users WITH async mode: Now works instead of throwing error - Future-proof: async mode will be default in Svelte 6
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@wobsoriano does this seem reasonable? |
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samwillis
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Approving but with the question - do we have a test that validates this statement:
The fix removes the flushSync call and updates status directly. Svelte's reactivity system handles the update automatically without needing synchronous flushing.
Add test to verify that status changes in useLiveQuery properly trigger reactive re-execution in Svelte effects. This validates that accessing query.isReady/isLoading in component templates will automatically re-render when status changes from loading to ready. The test uses $effect() to track execution counts, confirming that Svelte's $state reactivity system works correctly with the status updates that occur via the onFirstReady callback (which doesn't use flushSync in async compiler mode). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
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Ah good call — just added an actual test. |
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Regenerate docs after adding reactive status change test. All files now use correct PascalCase naming to match main branch. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
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Update React reference docs to include useLiveSuspenseQuery hook that was added in main. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
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Fixes #744
The flushSync() call inside the onFirstReady callback was breaking Svelte 5's async compiler mode. The async compiler enforces a rule that flushSync cannot be called inside effects, as documented at svelte.dev/e/flush_sync_in_effect.
The fix removes the flushSync call and updates status directly. Svelte's reactivity system handles the update automatically without needing synchronous flushing. This matches the pattern used in Vue's implementation.
Changes:
This fix is backward compatible:
🎯 Changes
✅ Checklist
pnpm test:pr.🚀 Release Impact