From a75866f34d5b64e0c40b2888a5f89a69ec1151f9 Mon Sep 17 00:00:00 2001
From: Artyom Alekseevich <47069814+FrankFMY@users.noreply.github.com>
Date: Thu, 5 Feb 2026 23:03:40 +0100
Subject: [PATCH] fix: detect store in each block expression regardless of AST
 shape (#17636)

The store invalidation detection in each blocks only checked for
Identifier and MemberExpression AST node types. This caused bind:
on iteration variables to silently fail when the expression used
logical operators (e.g. `{#each $store.items ?? [] as item}`).

Use expression metadata dependencies instead of AST type checking
to find store_sub bindings, which correctly handles all expression
shapes.

Fixes #14625
---
 .changeset/fix-each-bind-store-logical.md     |  5 +++++
 .../3-transform/client/visitors/EachBlock.js  | 12 ++++------
 .../store-each-binding-logical/_config.js     | 22 +++++++++++++++++++
 .../store-each-binding-logical/main.svelte    | 13 +++++++++++
 4 files changed, 44 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/fix-each-bind-store-logical.md
 create mode 100644 packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/_config.js
 create mode 100644 packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/main.svelte

diff --git a/.changeset/fix-each-bind-store-logical.md b/.changeset/fix-each-bind-store-logical.md
new file mode 100644
index 0000000000..1327015124
--- /dev/null
+++ b/.changeset/fix-each-bind-store-logical.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: detect store in each block expression regardless of AST shape
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/EachBlock.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/EachBlock.js
index b2724fa90f..a1371b516a 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/EachBlock.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/EachBlock.js
@@ -101,15 +101,11 @@ export function EachBlock(node, context) {
 	}
 
 	// If the array is a store expression, we need to invalidate it when the array is changed.
-	// This doesn't catch all cases, but all the ones that Svelte 4 catches, too.
 	let store_to_invalidate = '';
-	if (node.expression.type === 'Identifier' || node.expression.type === 'MemberExpression') {
-		const id = object(node.expression);
-		if (id) {
-			const binding = context.state.scope.get(id.name);
-			if (binding?.kind === 'store_sub') {
-				store_to_invalidate = id.name;
-			}
+	for (const binding of node.metadata.expression.dependencies) {
+		if (binding.kind === 'store_sub') {
+			store_to_invalidate = binding.node.name;
+			break;
 		}
 	}
 
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/_config.js
new file mode 100644
index 0000000000..1134b20d0c
--- /dev/null
+++ b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/_config.js
@@ -0,0 +1,22 @@
+import { flushSync } from 'svelte';
+import { ok, test } from '../../test';
+
+export default test({
+	test({ assert, target, window }) {
+		const input = target.querySelector('input');
+		ok(input);
+
+		const event = new window.Event('input');
+		input.value = 'changed';
+		input.dispatchEvent(event);
+		flushSync();
+
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+			<input>
+			<p>changed</p>
+		`
+		);
+	}
+});
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/main.svelte b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/main.svelte
new file mode 100644
index 0000000000..77731ea5a4
--- /dev/null
+++ b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-logical/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	import { writable } from 'svelte/store';
+
+	const items = writable([
+		{ id: 0, text: 'initial' }
+	]);
+</script>
+
+{#each $items ?? [] as item}
+	<input bind:value={item.text}>
+{/each}
+
+<p>{$items[0].text}</p>