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fix: generate correct code for each blocks with async body #16923

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Merged
merged 3 commits into from
Oct 9, 2025
Merged

fix: generate correct code for each blocks with async body #16923

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185298e
fix: generate correct code for `each` blocks with async body
paoloricciuti Oct 9, 2025
0414af0
fix: else branch of `each` block
paoloricciuti Oct 9, 2025
be4f838
chore: add expected html
paoloricciuti Oct 9, 2025
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5 changes: 5 additions & 0 deletions .changeset/wicked-goats-begin.md
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@@ -0,0 +1,5 @@
---
'svelte': patch
---

fix: generate correct code for `each` blocks with async body
6 changes: 4 additions & 2 deletions packages/svelte/src/compiler/phases/3-transform/server/visitors/EachBlock.js
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Expand Up @@ -32,7 +32,9 @@ export function EachBlock(node, context) {
each.push(b.let(node.index, index));
}

each.push(.../** @type {BlockStatement} */ (context.visit(node.body)).body);
const new_body = /** @type {BlockStatement} */ (context.visit(node.body)).body;

each.push(...(node.body.metadata.has_await ? [create_async_block(b.block(new_body))] : new_body));

const for_loop = b.for(
b.declaration('let', [
Expand All @@ -55,7 +57,7 @@ export function EachBlock(node, context) {
b.if(
b.binary('!==', b.member(array_id, 'length'), b.literal(0)),
b.block([open, for_loop]),
fallback
node.fallback.metadata.has_await ? create_async_block(fallback) : fallback
)
);
} else {
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5 changes: 5 additions & 0 deletions packages/svelte/tests/server-side-rendering/samples/each-body-async/_config.js
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import { test } from '../../test';

export default test({
mode: ['async']
});
5 changes: 5 additions & 0 deletions packages/svelte/tests/server-side-rendering/samples/each-body-async/main.svelte
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{#each { length: 1 } as _}
{@const data = await Promise.resolve("data")}
{:else}
{@const data = await Promise.resolve("data")}
{/each}
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