From 44bec4c8b172a47ff300f754463555bbb694bb05 Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Tue, 24 Jun 2025 23:35:40 +0200
Subject: [PATCH 1/6] fix: use fine grained for template if the component is
 not explicitly in legacy mode

---
 .changeset/cold-dingos-dream.md               |  5 +++++
 .../src/compiler/phases/2-analyze/index.js    | 20 +++++++++++++++++++
 .../client/visitors/shared/utils.js           |  2 +-
 .../svelte/src/compiler/phases/types.d.ts     |  1 +
 .../_config.js                                | 14 +++++++++++++
 .../main.svelte                               |  8 ++++++++
 .../test.svelte.js                            |  9 +++++++++
 .../_config.js                                | 14 +++++++++++++
 .../main.svelte                               |  9 +++++++++
 .../test.svelte.js                            |  9 +++++++++
 .../_config.js                                | 14 +++++++++++++
 .../main.svelte                               | 12 +++++++++++
 .../test.svelte.js                            |  9 +++++++++
 .../samples/legacy-runes-ambiguous/_config.js | 14 +++++++++++++
 .../legacy-runes-ambiguous/main.svelte        |  7 +++++++
 .../legacy-runes-ambiguous/test.svelte.js     |  9 +++++++++
 16 files changed, 155 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/cold-dingos-dream.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/test.svelte.js

diff --git a/.changeset/cold-dingos-dream.md b/.changeset/cold-dingos-dream.md
new file mode 100644
index 000000000000..c48414abc2b7
--- /dev/null
+++ b/.changeset/cold-dingos-dream.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: use fine grained for template if the component is not explicitly in legacy mode
diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index fded183b86c3..d11bd1e758de 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -431,6 +431,26 @@ export function analyze_component(root, source, options) {
 		template,
 		elements: [],
 		runes,
+		// if we are not in runes mode but we have no reserved references ($$props, $$restProps)
+		// and no `export let` we might be in a wannabe runes component that is using runes in an external
+		// module...we need to fallback to the runic behavior
+		maybe_runes:
+			!runes &&
+			// if they explicitly disabled runes, use the legacy behavior
+			options.runes !== false &&
+			!module.scope.references.keys().some((name) => ['$$props', '$$restProps'].includes(name)) &&
+			!instance.ast.body.some(
+				(node) =>
+					node.type === 'ExportNamedDeclaration' &&
+					((node.declaration &&
+						node.declaration.type === 'VariableDeclaration' &&
+						node.declaration.kind === 'let') ||
+						node.specifiers.some(
+							(specifier) =>
+								specifier.local.type === 'Identifier' &&
+								instance.scope.get(specifier.local.name)?.declaration_kind === 'let'
+						))
+			),
 		tracing: false,
 		classes: new Map(),
 		immutable: runes || options.immutable,
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
index 15982899c9d7..5ee962d0ae39 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
@@ -370,7 +370,7 @@ export function validate_mutation(node, context, expression) {
 export function build_expression(context, expression, metadata, state = context.state) {
 	const value = /** @type {Expression} */ (context.visit(expression, state));
 
-	if (context.state.analysis.runes) {
+	if (context.state.analysis.runes || context.state.analysis.maybe_runes) {
 		return value;
 	}
 
diff --git a/packages/svelte/src/compiler/phases/types.d.ts b/packages/svelte/src/compiler/phases/types.d.ts
index 67cbd75ff86f..8fa4bff61943 100644
--- a/packages/svelte/src/compiler/phases/types.d.ts
+++ b/packages/svelte/src/compiler/phases/types.d.ts
@@ -51,6 +51,7 @@ export interface ComponentAnalysis extends Analysis {
 	/** Used for CSS pruning and scoping */
 	elements: Array<AST.RegularElement | AST.SvelteElement>;
 	runes: boolean;
+	maybe_runes: boolean;
 	tracing: boolean;
 	exports: Array<{ name: string; alias: string | null }>;
 	/** Whether the component uses `$$props` */
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
new file mode 100644
index 000000000000..002b66b8e39c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
@@ -0,0 +1,14 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '0');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/main.svelte
new file mode 100644
index 000000000000..cb5837dcd6da
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/main.svelte
@@ -0,0 +1,8 @@
+<svelte:options runes={false} />
+<script>
+	import { get, set } from "./test.svelte.js";
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
new file mode 100644
index 000000000000..0610aed86538
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
@@ -0,0 +1,14 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '1');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/main.svelte
new file mode 100644
index 000000000000..49aef8151845
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	export const x = 42;
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
new file mode 100644
index 000000000000..0610aed86538
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
@@ -0,0 +1,14 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '1');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/main.svelte
new file mode 100644
index 000000000000..1449b7d5824c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/main.svelte
@@ -0,0 +1,12 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	let x = 42;
+
+	export { x };
+</script>
+
+{x}
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
new file mode 100644
index 000000000000..0610aed86538
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
@@ -0,0 +1,14 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '1');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/main.svelte
new file mode 100644
index 000000000000..698a852ac927
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/main.svelte
@@ -0,0 +1,7 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}

From 06ddc8cbb2490660fb2b37ce65beb4e5fd2193d0 Mon Sep 17 00:00:00 2001
From: Paolo Ricciuti <ricciutipaolo@gmail.com>
Date: Tue, 24 Jun 2025 23:57:55 +0200
Subject: [PATCH 2/6] chore: add comment

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
---
 .../phases/3-transform/client/visitors/shared/utils.js         | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
index 5ee962d0ae39..c861a51b7df2 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
@@ -370,6 +370,9 @@ export function validate_mutation(node, context, expression) {
 export function build_expression(context, expression, metadata, state = context.state) {
 	const value = /** @type {Expression} */ (context.visit(expression, state));
 
+	// Components not explicitly in legacy mode might be expected to be in runes mode (especially since we didn't
+	// adjust this behavior until recently, which broke people's existing components), so we also bail in this case.
+	// Kind of an in-between-mode.
 	if (context.state.analysis.runes || context.state.analysis.maybe_runes) {
 		return value;
 	}

From 5ec63e7809df578a63ade636e3984c74f4726315 Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Tue, 24 Jun 2025 23:58:38 +0200
Subject: [PATCH 3/6] fix: add `LabeledStatement` to `instance.ast` check

---
 .../src/compiler/phases/2-analyze/index.js    | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index d11bd1e758de..ab14d835441e 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -441,15 +441,16 @@ export function analyze_component(root, source, options) {
 			!module.scope.references.keys().some((name) => ['$$props', '$$restProps'].includes(name)) &&
 			!instance.ast.body.some(
 				(node) =>
-					node.type === 'ExportNamedDeclaration' &&
-					((node.declaration &&
-						node.declaration.type === 'VariableDeclaration' &&
-						node.declaration.kind === 'let') ||
-						node.specifiers.some(
-							(specifier) =>
-								specifier.local.type === 'Identifier' &&
-								instance.scope.get(specifier.local.name)?.declaration_kind === 'let'
-						))
+					node.type === 'LabeledStatement' ||
+					(node.type === 'ExportNamedDeclaration' &&
+						((node.declaration &&
+							node.declaration.type === 'VariableDeclaration' &&
+							node.declaration.kind === 'let') ||
+							node.specifiers.some(
+								(specifier) =>
+									specifier.local.type === 'Identifier' &&
+									instance.scope.get(specifier.local.name)?.declaration_kind === 'let'
+							)))
 			),
 		tracing: false,
 		classes: new Map(),

From 19bc230b2235fde9737b2aa3c589da09c22322b8 Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Wed, 25 Jun 2025 00:04:52 +0200
Subject: [PATCH 4/6] fix: spread `keys`

---
 packages/svelte/src/compiler/phases/2-analyze/index.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index ab14d835441e..80adc10c1ab7 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -438,7 +438,9 @@ export function analyze_component(root, source, options) {
 			!runes &&
 			// if they explicitly disabled runes, use the legacy behavior
 			options.runes !== false &&
-			!module.scope.references.keys().some((name) => ['$$props', '$$restProps'].includes(name)) &&
+			![...module.scope.references.keys()].some((name) =>
+				['$$props', '$$restProps'].includes(name)
+			) &&
 			!instance.ast.body.some(
 				(node) =>
 					node.type === 'LabeledStatement' ||

From 5b426bc8e259c6916d643b23d45e97af8e5a6cd5 Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Wed, 25 Jun 2025 00:09:13 +0200
Subject: [PATCH 5/6] fix: snapshots

---
 .../samples/purity/_expected/client/index.svelte.js         | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js b/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
index da6fdf44d881..a351851875ed 100644
--- a/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
@@ -8,13 +8,11 @@ export default function Purity($$anchor) {
 	var fragment = root();
 	var p = $.first_child(fragment);
 
-	p.textContent = (
-		$.untrack(() => Math.max(0, Math.min(0, 100)))
-	);
+	p.textContent = '0';
 
 	var p_1 = $.sibling(p, 2);
 
-	p_1.textContent = ($.untrack(() => location.href));
+	p_1.textContent = location.href;
 
 	var node = $.sibling(p_1, 2);
 

From ed16aa2a8196f626f8c876781c3a325de11c976f Mon Sep 17 00:00:00 2001
From: paoloricciuti <ricciutipaolo@gmail.com>
Date: Wed, 25 Jun 2025 00:21:29 +0200
Subject: [PATCH 6/6] fix: use `compileOption.runes` if defined + add other
 tests

---
 packages/svelte/tests/runtime-legacy/shared.ts  |  5 ++++-
 .../_config.js                                  |  3 +++
 .../_config.js                                  | 17 +++++++++++++++++
 .../main.svelte                                 |  9 +++++++++
 .../test.svelte.js                              |  9 +++++++++
 .../_config.js                                  | 17 +++++++++++++++++
 .../main.svelte                                 |  9 +++++++++
 .../test.svelte.js                              |  9 +++++++++
 .../_config.js                                  |  3 +++
 .../_config.js                                  | 17 +++++++++++++++++
 .../main.svelte                                 |  9 +++++++++
 .../test.svelte.js                              |  9 +++++++++
 .../_config.js                                  | 17 +++++++++++++++++
 .../main.svelte                                 | 10 ++++++++++
 .../test.svelte.js                              |  9 +++++++++
 .../_config.js                                  |  5 ++++-
 .../samples/legacy-runes-ambiguous/_config.js   |  3 +++
 17 files changed, 158 insertions(+), 2 deletions(-)
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/test.svelte.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/test.svelte.js

diff --git a/packages/svelte/tests/runtime-legacy/shared.ts b/packages/svelte/tests/runtime-legacy/shared.ts
index 11ea9f6dda89..126992a0c070 100644
--- a/packages/svelte/tests/runtime-legacy/shared.ts
+++ b/packages/svelte/tests/runtime-legacy/shared.ts
@@ -158,7 +158,10 @@ async function common_setup(cwd: string, runes: boolean | undefined, config: Run
 		...config.compileOptions,
 		immutable: config.immutable,
 		accessors: 'accessors' in config ? config.accessors : true,
-		runes
+		runes:
+			config.compileOptions && 'runes' in config.compileOptions
+				? config.compileOptions.runes
+				: runes
 	};
 
 	// load_compiled can be used for debugging a test. It means the compiler will not run on the input
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
index 002b66b8e39c..904fea3f653c 100644
--- a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-explicit-false/_config.js
@@ -3,6 +3,9 @@ import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
 	async test({ assert, target }) {
 		const p = target.querySelector('p');
 		const btn = target.querySelector('button');
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/_config.js
new file mode 100644
index 000000000000..904fea3f653c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/_config.js
@@ -0,0 +1,17 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '0');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/main.svelte
new file mode 100644
index 000000000000..a7370b48d6d2
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	$$props;
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$props/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/_config.js
new file mode 100644
index 000000000000..904fea3f653c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/_config.js
@@ -0,0 +1,17 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '0');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/main.svelte
new file mode 100644
index 000000000000..ccf9bd28642c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	$$restProps;
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-$$restProps/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
index 0610aed86538..2d72de6d134d 100644
--- a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-const/_config.js
@@ -3,6 +3,9 @@ import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
 	async test({ assert, target }) {
 		const p = target.querySelector('p');
 		const btn = target.querySelector('button');
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/_config.js
new file mode 100644
index 000000000000..904fea3f653c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/_config.js
@@ -0,0 +1,17 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '0');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/main.svelte
new file mode 100644
index 000000000000..f7cd0ede2e39
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	$: console.log("");
+</script>
+
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-labeled/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/_config.js
new file mode 100644
index 000000000000..904fea3f653c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/_config.js
@@ -0,0 +1,17 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
+	async test({ assert, target }) {
+		const p = target.querySelector('p');
+		const btn = target.querySelector('button');
+		flushSync(() => {
+			btn?.click();
+		});
+		assert.equal(p?.innerHTML, '0');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/main.svelte b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/main.svelte
new file mode 100644
index 000000000000..36becde4a300
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/main.svelte
@@ -0,0 +1,10 @@
+<script>
+	import { get, set } from "./test.svelte.js";
+
+	export let x = 42;
+</script>
+
+{x}
+<p>{get()}</p>
+
+<button onclick={()=>set()}></button>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/test.svelte.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/test.svelte.js
new file mode 100644
index 000000000000..f0e7181c29cc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let-2/test.svelte.js
@@ -0,0 +1,9 @@
+let count = $state(0);
+
+export function get() {
+	return count;
+}
+
+export function set() {
+	count++;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
index 0610aed86538..904fea3f653c 100644
--- a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous-export-let/_config.js
@@ -3,12 +3,15 @@ import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
 	async test({ assert, target }) {
 		const p = target.querySelector('p');
 		const btn = target.querySelector('button');
 		flushSync(() => {
 			btn?.click();
 		});
-		assert.equal(p?.innerHTML, '1');
+		assert.equal(p?.innerHTML, '0');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
index 0610aed86538..2d72de6d134d 100644
--- a/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/legacy-runes-ambiguous/_config.js
@@ -3,6 +3,9 @@ import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
+	compileOptions: {
+		runes: undefined
+	},
 	async test({ assert, target }) {
 		const p = target.querySelector('p');
 		const btn = target.querySelector('button');