fix: propagate async @const blockers through closure references#18309
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Rich-Harris
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This PR was opened by the [Changesets release](https://github.com/changesets/action) GitHub action. When you're ready to do a release, you can merge this and the packages will be published to npm automatically. If you're not ready to do a release yet, that's fine, whenever you add more changesets to main, this PR will be updated. # Releases ## svelte@5.55.10 ### Patch Changes - fix: unlink errored and otherwise finished batch ([#18264](#18264)) - perf: walk composedPath() directly in delegated event propagation ([#18268](#18268)) - fix: transfer effects when merging batches ([#18254](#18254)) - fix: allow `$derived(await ...)` in disconnected effect roots ([#18273](#18273)) - fix: remove temporary raw-text hydration markers ([#18269](#18269)) - fix: propagate async `@const` blockers through closure references so template expressions like `{(() => host)()}` correctly wait for the awaited value ([#18309](#18309)) - fix: properly unlink batches ([#18298](#18298)) - fix: settle discarded batch ([#18290](#18290)) - fix: declare `let:` directives before `{@const}` declarations on slotted elements ([#18271](#18271)) - fix: resume outro-ed branches if they were kept around ([#18291](#18291)) - fix: avoid waterfall-warning when async resolves to same value ([#18297](#18297)) - fix: correctly coordinate component-level effects inside async blocks ([#18260](#18260)) - fix: make unnecessary commit work less likely ([#18263](#18263)) - chore: add tag name to `a11y_click_events_have_key_events` warning ([#18272](#18272)) - fix: catch rejected promises while merging/committing ([#18266](#18266)) Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
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Right now, if you have the following:
{@const data = await foo} <p>{(() => data)()}<p>It will blow up during CSR, because it tries to read
databefore it exists. The solution to this is to consider references inside closures as blockers for those closures. This does mean we'll overblock in some circumstances, such as:{@const data = await foo} <button onclick={() => data}>foo<button>But I wonder if that's actually incorrect? If the user were to click
onclickbeforedatais ready, it would blow up.