fix: improve non state referenced warning (#9809)

* fix: improve non state referenced warning

* add test

.changeset/polite-dolphins-care.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: improve non state referenced warning

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

@@ -409,10 +409,10 @@ export function analyze_component(root, options) {
 		analysis.reactive_statements = order_reactive_statements(analysis.reactive_statements);
 	}
 
-	// warn on any nonstate declarations that are a) mutated and b) referenced in the template
+	// warn on any nonstate declarations that are a) reassigned and mutated and b) referenced in the template
 	for (const scope of [module.scope, instance.scope]) {
 		outer: for (const [name, binding] of scope.declarations) {
-			if (binding.kind === 'normal' && binding.mutated) {
+			if (binding.kind === 'normal' && binding.reassigned && binding.mutated) {
 				for (const { path } of binding.references) {
 					if (path[0].type !== 'Fragment') continue;
 					for (let i = 1; i < path.length; i += 1) {

packages/svelte/tests/validator/samples/runes-referenced-nonstate-2/_config.js

@@ -0,0 +1,3 @@
+import { test } from '../../test';
+
+export default test({});

packages/svelte/tests/validator/samples/runes-referenced-nonstate-2/input.svelte

@@ -0,0 +1,6 @@
+<script>
+	let a = $state({b: 0});
+</script>
+
+<button onclick={() => a.b += 1}>a += 1</button>
+<p>{JSON.stringify(a)} + {a.b}</p>

packages/svelte/tests/validator/samples/runes-referenced-nonstate-2/warnings.json

@@ -0,0 +1 @@
+[]