further improvements

packages/svelte/src/compiler/phases/2-analyze/validation.js

@@ -721,7 +721,7 @@ function validate_call_expression(node, scope, path) {
 		if (
 			node.arguments.length === 1 &&
 			node.arguments[0].type !== 'SpreadElement' &&
-			should_proxy_or_freeze(node.arguments[0])
+			should_proxy_or_freeze(node.arguments[0], scope)
 		) {
 			return;
 		}

packages/svelte/src/compiler/phases/3-transform/client/utils.js

@@ -293,7 +293,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					if (
 						context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 					) {
 						const assignment = fallback();
 						if (assignment.type === 'AssignmentExpression') {
@@ -310,7 +310,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 						left,
 						context.state.analysis.runes &&
 							!options?.skip_proxy_and_freeze &&
-							should_proxy_or_freeze(value)
+							should_proxy_or_freeze(value, context.state.scope)
 							? private_state.kind === 'frozen_state'
 								? b.call('$.freeze', value)
 								: b.call('$.proxy', value)
@@ -330,7 +330,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 				context.state.analysis.runes &&
 				public_state !== undefined &&
 				!options?.skip_proxy_and_freeze &&
-				should_proxy_or_freeze(value)
+				should_proxy_or_freeze(value, context.state.scope)
 			) {
 				const assignment = fallback();
 				if (assignment.type === 'AssignmentExpression') {
@@ -398,7 +398,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					b.id(left_name),
 					context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 						? b.call('$.proxy', value)
 						: value
 				);
@@ -408,7 +408,7 @@ export function serialize_set_binding(node, context, fallback, options) {
 					b.id(left_name),
 					context.state.analysis.runes &&
 						!options?.skip_proxy_and_freeze &&
-						should_proxy_or_freeze(value)
+						should_proxy_or_freeze(value, context.state.scope)
 						? b.call('$.freeze', value)
 						: value
 				);
@@ -623,8 +623,11 @@ export function get_prop_source(binding, state, name, initial) {
 	return b.call('$.prop', ...args);
 }
 
-/** @param {import('estree').Expression} node */
-export function should_proxy_or_freeze(node) {
+/**
+ * @param {import('estree').Expression} node
+ * @param {import("../../scope.js").Scope | null} scope
+ */
+export function should_proxy_or_freeze(node, scope) {
 	if (
 		!node ||
 		node.type === 'Literal' ||
@@ -637,5 +640,20 @@ export function should_proxy_or_freeze(node) {
 	) {
 		return false;
 	}
+	if (node.type === 'Identifier' && scope !== null) {
+		const binding = scope.get(node.name);
+		// Let's see if the reference is something that can be proxied or frozen
+		if (
+			binding !== null &&
+			!binding.reassigned &&
+			binding.initial !== null &&
+			binding.initial.type !== 'FunctionDeclaration' &&
+			binding.initial.type !== 'ClassDeclaration' &&
+			binding.initial.type !== 'ImportDeclaration' &&
+			binding.initial.type !== 'EachBlock'
+		) {
+			return should_proxy_or_freeze(binding.initial, null);
+		}
+	}
 	return true;
 }

packages/svelte/src/compiler/phases/3-transform/client/visitors/javascript-runes.js

@@ -85,11 +85,14 @@ export const javascript_visitors_runes = {
 
 						value =
 							field.kind === 'state'
-								? b.call('$.source', should_proxy_or_freeze(init) ? b.call('$.proxy', init) : init)
+								? b.call(
+										'$.source',
+										should_proxy_or_freeze(init, state.scope) ? b.call('$.proxy', init) : init
+									)
 								: field.kind === 'frozen_state'
 									? b.call(
 											'$.source',
-											should_proxy_or_freeze(init) ? b.call('$.freeze', init) : init
+											should_proxy_or_freeze(init, state.scope) ? b.call('$.freeze', init) : init
 										)
 									: b.call('$.derived', b.thunk(init));
 					} else {
@@ -238,7 +241,7 @@ export const javascript_visitors_runes = {
 				 */
 				const create_state_declarator = (id, value) => {
 					const binding = /** @type {import('#compiler').Binding} */ (state.scope.get(id.name));
-					if (should_proxy_or_freeze(value)) {
+					if (should_proxy_or_freeze(value, state.scope)) {
 						value = b.call(rune === '$state' ? '$.proxy' : '$.freeze', value);
 					}
 					if (is_state_source(binding, state)) {

packages/svelte/tests/compiler-errors/samples/runes-wrong-state-placement-3/_config.js

@@ -0,0 +1,10 @@
+import { test } from '../../test';
+
+export default test({
+	error: {
+		code: 'invalid-state-location',
+		message:
+			'$state() can only be used as a variable declaration initializer, a class field or if passed an object or array, can be used as an expression',
+		position: [113, 124]
+	}
+});

packages/svelte/tests/compiler-errors/samples/runes-wrong-state-placement-3/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	function a() {
+		let ref = { a: 1 };
+		return $state(ref);
+	}
+
+	function b() {
+		let ref = 1;
+		return $state(ref);
+	}
+</script>